diff --git a/resources/celerity/map.php b/resources/celerity/map.php
index 056535074c..65eed7916a 100644
--- a/resources/celerity/map.php
+++ b/resources/celerity/map.php
@@ -12,7 +12,7 @@ return array(
     'core.pkg.css' => '261ee8cf',
     'core.pkg.js' => '5ace8a1e',
     'differential.pkg.css' => 'c3f15714',
-    'differential.pkg.js' => '67c9ea4c',
+    'differential.pkg.js' => 'be031567',
     'diffusion.pkg.css' => '42c75c37',
     'diffusion.pkg.js' => '91192d85',
     'maniphest.pkg.css' => '35995d6d',
@@ -374,7 +374,7 @@ return array(
     'rsrc/js/application/dashboard/behavior-dashboard-move-panels.js' => '076bd092',
     'rsrc/js/application/dashboard/behavior-dashboard-query-panel-select.js' => '1e413dc9',
     'rsrc/js/application/dashboard/behavior-dashboard-tab-panel.js' => '9b1cbd76',
-    'rsrc/js/application/diff/DiffChangeset.js' => 'e7cf10d6',
+    'rsrc/js/application/diff/DiffChangeset.js' => 'd0a85a85',
     'rsrc/js/application/diff/DiffChangesetList.js' => 'b91204e9',
     'rsrc/js/application/diff/DiffInline.js' => 'a4a14a94',
     'rsrc/js/application/diff/behavior-preview-link.js' => 'f51e9c17',
@@ -753,7 +753,7 @@ return array(
     'phabricator-darklog' => '3b869402',
     'phabricator-darkmessage' => '26cd4b73',
     'phabricator-dashboard-css' => '4267d6c6',
-    'phabricator-diff-changeset' => 'e7cf10d6',
+    'phabricator-diff-changeset' => 'd0a85a85',
     'phabricator-diff-changeset-list' => 'b91204e9',
     'phabricator-diff-inline' => 'a4a14a94',
     'phabricator-drag-and-drop-file-upload' => '4370900d',
@@ -1973,6 +1973,17 @@ return array(
       'javelin-stratcom',
       'javelin-util',
     ),
+    'd0a85a85' => array(
+      'javelin-dom',
+      'javelin-util',
+      'javelin-stratcom',
+      'javelin-install',
+      'javelin-workflow',
+      'javelin-router',
+      'javelin-behavior-device',
+      'javelin-vector',
+      'phabricator-diff-inline',
+    ),
     'd12d214f' => array(
       'javelin-install',
       'javelin-dom',
@@ -2038,17 +2049,6 @@ return array(
       'javelin-dom',
       'phabricator-draggable-list',
     ),
-    'e7cf10d6' => array(
-      'javelin-dom',
-      'javelin-util',
-      'javelin-stratcom',
-      'javelin-install',
-      'javelin-workflow',
-      'javelin-router',
-      'javelin-behavior-device',
-      'javelin-vector',
-      'phabricator-diff-inline',
-    ),
     'e8240b50' => array(
       'javelin-behavior',
       'javelin-stratcom',
diff --git a/src/applications/config/check/PhabricatorExtraConfigSetupCheck.php b/src/applications/config/check/PhabricatorExtraConfigSetupCheck.php
index a742e3b82b..b676063e8c 100644
--- a/src/applications/config/check/PhabricatorExtraConfigSetupCheck.php
+++ b/src/applications/config/check/PhabricatorExtraConfigSetupCheck.php
@@ -533,6 +533,8 @@ final class PhabricatorExtraConfigSetupCheck extends PhabricatorSetupCheck {
         'This ancient extension point has been replaced with other '.
         'mechanisms, including "AphrontSite".'),
 
+      'differential.whitespace-matters' => pht(
+        'Whitespace rendering is now handled automatically.'),
     );
 
     return $ancient_config;
diff --git a/src/applications/differential/__tests__/DifferentialParseRenderTestCase.php b/src/applications/differential/__tests__/DifferentialParseRenderTestCase.php
index c278ff0c67..259bb671de 100644
--- a/src/applications/differential/__tests__/DifferentialParseRenderTestCase.php
+++ b/src/applications/differential/__tests__/DifferentialParseRenderTestCase.php
@@ -31,7 +31,6 @@ final class DifferentialParseRenderTestCase extends PhabricatorTestCase {
       foreach (array('one', 'two') as $type) {
         $this->runParser($type, $data, $file, 'expect');
         $this->runParser($type, $data, $file, 'unshielded');
-        $this->runParser($type, $data, $file, 'whitespace');
       }
     }
   }
@@ -44,25 +43,20 @@ final class DifferentialParseRenderTestCase extends PhabricatorTestCase {
     }
 
     $unshielded = false;
-    $whitespace = false;
     switch ($extension) {
       case 'unshielded':
         $unshielded = true;
         break;
-      case 'whitespace';
-        $unshielded = true;
-        $whitespace = true;
-        break;
     }
 
     $parsers = $this->buildChangesetParsers($type, $data, $file);
-    $actual = $this->renderParsers($parsers, $unshielded, $whitespace);
+    $actual = $this->renderParsers($parsers, $unshielded);
     $expect = Filesystem::readFile($test_file);
 
     $this->assertEqual($expect, $actual, basename($test_file));
   }
 
-  private function renderParsers(array $parsers, $unshield, $whitespace) {
+  private function renderParsers(array $parsers, $unshield) {
     $result = array();
     foreach ($parsers as $parser) {
       if ($unshield) {
@@ -73,11 +67,6 @@ final class DifferentialParseRenderTestCase extends PhabricatorTestCase {
         $e_range = null;
       }
 
-      if ($whitespace) {
-        $parser->setWhitespaceMode(
-          DifferentialChangesetParser::WHITESPACE_SHOW_ALL);
-      }
-
       $result[] = $parser->render($s_range, $e_range, array());
     }
     return implode(str_repeat('~', 80)."\n", $result);
diff --git a/src/applications/differential/__tests__/data/generated.diff.one.unshielded b/src/applications/differential/__tests__/data/generated.diff.one.unshielded
index ca4b1b167e..acfa701c8b 100644
--- a/src/applications/differential/__tests__/data/generated.diff.one.unshielded
+++ b/src/applications/differential/__tests__/data/generated.diff.one.unshielded
@@ -1,6 +1,5 @@
 N 1 . @generated\n~
-O 2 - \n~
+N 2 . \n~
 O 3 - This is a generated file.\n~
-N 2 + \n~
 N 3 + This is a generated file{(, full of generated code)}.\n~
 N 4 . \n~
diff --git a/src/applications/differential/__tests__/data/generated.diff.two.unshielded b/src/applications/differential/__tests__/data/generated.diff.two.unshielded
index 967f6220de..183a0b6edc 100644
--- a/src/applications/differential/__tests__/data/generated.diff.two.unshielded
+++ b/src/applications/differential/__tests__/data/generated.diff.two.unshielded
@@ -1,7 +1,7 @@
 O 1 . @generated\n~
 N 1 . @generated\n~
-O 2 - \n~
-N 2 + \n~
+O 2 . \n~
+N 2 . \n~
 O 3 - This is a generated file.\n~
 N 3 + This is a generated file{(, full of generated code)}.\n~
 O 4 . \n~
diff --git a/src/applications/differential/__tests__/data/whitespace.diff.one.expect b/src/applications/differential/__tests__/data/whitespace.diff.one.expect
index 5b229959d3..87ad1dcdd9 100644
--- a/src/applications/differential/__tests__/data/whitespace.diff.one.expect
+++ b/src/applications/differential/__tests__/data/whitespace.diff.one.expect
@@ -2,4 +2,5 @@ CTYPE 2 1 (unforced)
 WHITESPACE
 WHITESPACE
 -
-SHIELD (whitespace) This file was changed only by adding or removing whitespace.
+O 1 - -=[-Rocket-Ship>\n~
+N 1 + {>          )}-=[-Rocket-Ship>\n~
diff --git a/src/applications/differential/__tests__/data/whitespace.diff.two.expect b/src/applications/differential/__tests__/data/whitespace.diff.two.expect
index 5b229959d3..87ad1dcdd9 100644
--- a/src/applications/differential/__tests__/data/whitespace.diff.two.expect
+++ b/src/applications/differential/__tests__/data/whitespace.diff.two.expect
@@ -2,4 +2,5 @@ CTYPE 2 1 (unforced)
 WHITESPACE
 WHITESPACE
 -
-SHIELD (whitespace) This file was changed only by adding or removing whitespace.
+O 1 - -=[-Rocket-Ship>\n~
+N 1 + {>          )}-=[-Rocket-Ship>\n~
diff --git a/src/applications/differential/config/PhabricatorDifferentialConfigOptions.php b/src/applications/differential/config/PhabricatorDifferentialConfigOptions.php
index ec2099f8dd..9634756dac 100644
--- a/src/applications/differential/config/PhabricatorDifferentialConfigOptions.php
+++ b/src/applications/differential/config/PhabricatorDifferentialConfigOptions.php
@@ -80,18 +80,6 @@ EOHELP
             "Select and reorder revision fields.\n\n".
             "NOTE: This feature is under active development and subject ".
             "to change.")),
-      $this->newOption(
-        'differential.whitespace-matters',
-        'list<regex>',
-        array(
-          '/\.py$/',
-          '/\.l?hs$/',
-          '/\.ya?ml$/',
-        ))
-        ->setDescription(
-          pht(
-            "List of file regexps where whitespace is meaningful and should ".
-            "not use 'ignore-all' by default")),
       $this->newOption('differential.require-test-plan-field', 'bool', true)
         ->setBoolOptions(
           array(
diff --git a/src/applications/differential/controller/DifferentialRevisionViewController.php b/src/applications/differential/controller/DifferentialRevisionViewController.php
index 9bc6345576..2ac1d30eca 100644
--- a/src/applications/differential/controller/DifferentialRevisionViewController.php
+++ b/src/applications/differential/controller/DifferentialRevisionViewController.php
@@ -305,10 +305,6 @@ final class DifferentialRevisionViewController
     $details = $this->buildDetails($revision, $field_list);
     $curtain = $this->buildCurtain($revision);
 
-    $whitespace = $request->getStr(
-      'whitespace',
-      DifferentialChangesetParser::WHITESPACE_IGNORE_MOST);
-
     $repository = $revision->getRepository();
     if ($repository) {
       $symbol_indexes = $this->buildSymbolIndexes(
@@ -383,7 +379,6 @@ final class DifferentialRevisionViewController
         ->setDiff($target)
         ->setRenderingReferences($rendering_references)
         ->setVsMap($vs_map)
-        ->setWhitespace($whitespace)
         ->setSymbolIndexes($symbol_indexes)
         ->setTitle(pht('Diff %s', $target->getID()))
         ->setBackground(PHUIObjectBoxView::BLUE_PROPERTY);
@@ -412,7 +407,6 @@ final class DifferentialRevisionViewController
       ->setDiffUnitStatuses($broken_diffs)
       ->setSelectedVersusDiffID($diff_vs)
       ->setSelectedDiffID($target->getID())
-      ->setSelectedWhitespace($whitespace)
       ->setCommitsForLinks($commits_for_links);
 
     $local_table = id(new DifferentialLocalCommitsView())
@@ -1095,7 +1089,7 @@ final class DifferentialRevisionViewController
     // this ends up being something like
     //   D123.diff
     // or the verbose
-    //   D123.vs123.id123.whitespaceignore-all.diff
+    //   D123.vs123.id123.highlightjs.diff
     // lame but nice to include these options
     $file_name = ltrim($request_uri->getPath(), '/').'.';
     foreach ($request_uri->getQueryParamsAsPairList() as $pair) {
diff --git a/src/applications/differential/parser/DifferentialChangesetParser.php b/src/applications/differential/parser/DifferentialChangesetParser.php
index 22f31b3e9f..caa7463672 100644
--- a/src/applications/differential/parser/DifferentialChangesetParser.php
+++ b/src/applications/differential/parser/DifferentialChangesetParser.php
@@ -19,7 +19,6 @@ final class DifferentialChangesetParser extends Phobject {
   protected $specialAttributes = array();
 
   protected $changeset;
-  protected $whitespaceMode = null;
 
   protected $renderCacheKey = null;
 
@@ -163,7 +162,6 @@ final class DifferentialChangesetParser extends Phobject {
   }
 
   public function readParametersFromRequest(AphrontRequest $request) {
-    $this->setWhitespaceMode($request->getStr('whitespace'));
     $this->setCharacterEncoding($request->getStr('encoding'));
     $this->setHighlightAs($request->getStr('highlight'));
 
@@ -191,20 +189,14 @@ final class DifferentialChangesetParser extends Phobject {
     return $this;
   }
 
-  const CACHE_VERSION = 12;
+  const CACHE_VERSION = 13;
   const CACHE_MAX_SIZE = 8e6;
 
   const ATTR_GENERATED  = 'attr:generated';
   const ATTR_DELETED    = 'attr:deleted';
   const ATTR_UNCHANGED  = 'attr:unchanged';
-  const ATTR_WHITELINES = 'attr:white';
   const ATTR_MOVEAWAY   = 'attr:moveaway';
 
-  const WHITESPACE_SHOW_ALL         = 'show-all';
-  const WHITESPACE_IGNORE_TRAILING  = 'ignore-trailing';
-  const WHITESPACE_IGNORE_MOST      = 'ignore-most';
-  const WHITESPACE_IGNORE_ALL       = 'ignore-all';
-
   public function setOldLines(array $lines) {
     $this->old = $lines;
     return $this;
@@ -336,11 +328,6 @@ final class DifferentialChangesetParser extends Phobject {
     return $this;
   }
 
-  public function setWhitespaceMode($whitespace_mode) {
-    $this->whitespaceMode = $whitespace_mode;
-    return $this;
-  }
-
   public function setRenderingReference($ref) {
     $this->renderingReference = $ref;
     return $this;
@@ -574,10 +561,6 @@ final class DifferentialChangesetParser extends Phobject {
     return idx($this->specialAttributes, self::ATTR_UNCHANGED, false);
   }
 
-  public function isWhitespaceOnly() {
-    return idx($this->specialAttributes, self::ATTR_WHITELINES, false);
-  }
-
   public function isMoveAway() {
     return idx($this->specialAttributes, self::ATTR_MOVEAWAY, false);
   }
@@ -624,18 +607,8 @@ final class DifferentialChangesetParser extends Phobject {
   }
 
   private function tryCacheStuff() {
-    $whitespace_mode = $this->whitespaceMode;
-    switch ($whitespace_mode) {
-      case self::WHITESPACE_SHOW_ALL:
-      case self::WHITESPACE_IGNORE_TRAILING:
-      case self::WHITESPACE_IGNORE_ALL:
-        break;
-      default:
-        $whitespace_mode = self::WHITESPACE_IGNORE_MOST;
-        break;
-    }
+    $skip_cache = false;
 
-    $skip_cache = ($whitespace_mode != self::WHITESPACE_IGNORE_MOST);
     if ($this->disableCache) {
       $skip_cache = true;
     }
@@ -648,8 +621,6 @@ final class DifferentialChangesetParser extends Phobject {
       $skip_cache = true;
     }
 
-    $this->whitespaceMode = $whitespace_mode;
-
     $changeset = $this->changeset;
 
     if ($changeset->getFileType() != DifferentialChangeType::FILE_TEXT &&
@@ -668,71 +639,10 @@ final class DifferentialChangesetParser extends Phobject {
   }
 
   private function process() {
-    $whitespace_mode = $this->whitespaceMode;
     $changeset = $this->changeset;
 
-    $ignore_all = (($whitespace_mode == self::WHITESPACE_IGNORE_MOST) ||
-                  ($whitespace_mode == self::WHITESPACE_IGNORE_ALL));
-
-    $force_ignore = ($whitespace_mode == self::WHITESPACE_IGNORE_ALL);
-
-    if (!$force_ignore) {
-      if ($ignore_all && $changeset->getWhitespaceMatters()) {
-        $ignore_all = false;
-      }
-    }
-
-    // The "ignore all whitespace" algorithm depends on rediffing the
-    // files, and we currently need complete representations of both
-    // files to do anything reasonable. If we only have parts of the files,
-    // don't use the "ignore all" algorithm.
-    if ($ignore_all) {
-      $hunks = $changeset->getHunks();
-      if (count($hunks) !== 1) {
-        $ignore_all = false;
-      } else {
-        $first_hunk = reset($hunks);
-        if ($first_hunk->getOldOffset() != 1 ||
-            $first_hunk->getNewOffset() != 1) {
-            $ignore_all = false;
-        }
-      }
-    }
-
-    if ($ignore_all) {
-      $old_file = $changeset->makeOldFile();
-      $new_file = $changeset->makeNewFile();
-      if ($old_file == $new_file) {
-        // If the old and new files are exactly identical, the synthetic
-        // diff below will give us nonsense and whitespace modes are
-        // irrelevant anyway. This occurs when you, e.g., copy a file onto
-        // itself in Subversion (see T271).
-        $ignore_all = false;
-      }
-    }
-
     $hunk_parser = new DifferentialHunkParser();
-    $hunk_parser->setWhitespaceMode($whitespace_mode);
     $hunk_parser->parseHunksForLineData($changeset->getHunks());
-
-    // Depending on the whitespace mode, we may need to compute a different
-    // set of changes than the set of changes in the hunk data (specifically,
-    // we might want to consider changed lines which have only whitespace
-    // changes as unchanged).
-    if ($ignore_all) {
-      $engine = new PhabricatorDifferenceEngine();
-      $engine->setIgnoreWhitespace(true);
-      $no_whitespace_changeset = $engine->generateChangesetFromFileContent(
-        $old_file,
-        $new_file);
-
-      $type_parser = new DifferentialHunkParser();
-      $type_parser->parseHunksForLineData($no_whitespace_changeset->getHunks());
-
-      $hunk_parser->setOldLineTypeMap($type_parser->getOldLineTypeMap());
-      $hunk_parser->setNewLineTypeMap($type_parser->getNewLineTypeMap());
-    }
-
     $hunk_parser->reparseHunksForSpecialAttributes();
 
     $unchanged = false;
@@ -753,7 +663,6 @@ final class DifferentialChangesetParser extends Phobject {
     $this->setSpecialAttributes(array(
       self::ATTR_UNCHANGED  => $unchanged,
       self::ATTR_DELETED    => $hunk_parser->getIsDeleted(),
-      self::ATTR_WHITELINES => !$hunk_parser->getHasTextChanges(),
       self::ATTR_MOVEAWAY   => $moveaway,
     ));
 
@@ -971,10 +880,6 @@ final class DifferentialChangesetParser extends Phobject {
             pht('The contents of this file were not changed.'),
             $type);
         }
-      } else if ($this->isWhitespaceOnly()) {
-        $shield = $renderer->renderShield(
-          pht('This file was changed only by adding or removing whitespace.'),
-          'whitespace');
       } else if ($this->isDeleted()) {
         $shield = $renderer->renderShield(
           pht('This file was completely deleted.'));
diff --git a/src/applications/differential/parser/DifferentialHunkParser.php b/src/applications/differential/parser/DifferentialHunkParser.php
index e7b9ce21a9..d89089a7e7 100644
--- a/src/applications/differential/parser/DifferentialHunkParser.php
+++ b/src/applications/differential/parser/DifferentialHunkParser.php
@@ -7,7 +7,6 @@ final class DifferentialHunkParser extends Phobject {
   private $intraLineDiffs;
   private $depthOnlyLines;
   private $visibleLinesMask;
-  private $whitespaceMode;
 
   /**
    * Get a map of lines on which hunks start, other than line 1. This
@@ -125,21 +124,6 @@ final class DifferentialHunkParser extends Phobject {
     return $this->depthOnlyLines;
   }
 
-  public function setWhitespaceMode($white_space_mode) {
-    $this->whitespaceMode = $white_space_mode;
-    return $this;
-  }
-
-  private function getWhitespaceMode() {
-    if ($this->whitespaceMode === null) {
-      throw new Exception(
-        pht(
-          'You must %s before accessing this data.',
-          'setWhitespaceMode'));
-    }
-    return $this->whitespaceMode;
-  }
-
   public function getIsDeleted() {
     foreach ($this->getNewLines() as $line) {
       if ($line) {
@@ -159,13 +143,6 @@ final class DifferentialHunkParser extends Phobject {
     return false;
   }
 
-  /**
-   * Returns true if the hunks change any text, not just whitespace.
-   */
-  public function getHasTextChanges() {
-    return $this->getHasChanges('text');
-  }
-
   /**
    * Returns true if the hunks change anything, including whitespace.
    */
@@ -193,9 +170,6 @@ final class DifferentialHunkParser extends Phobject {
       }
 
       if ($o['type'] !== $n['type']) {
-        // The types are different, so either the underlying text is actually
-        // different or whatever whitespace rules we're using consider them
-        // different.
         return true;
       }
 
@@ -278,63 +252,6 @@ final class DifferentialHunkParser extends Phobject {
     $this->setOldLines($rebuild_old);
     $this->setNewLines($rebuild_new);
 
-    $this->updateChangeTypesForWhitespaceMode();
-
-    return $this;
-  }
-
-  private function updateChangeTypesForWhitespaceMode() {
-    $mode = $this->getWhitespaceMode();
-
-    $mode_show_all = DifferentialChangesetParser::WHITESPACE_SHOW_ALL;
-    if ($mode === $mode_show_all) {
-      // If we're showing all whitespace, we don't need to perform any updates.
-      return;
-    }
-
-    $mode_trailing = DifferentialChangesetParser::WHITESPACE_IGNORE_TRAILING;
-    $is_trailing = ($mode === $mode_trailing);
-
-    $new = $this->getNewLines();
-    $old = $this->getOldLines();
-    foreach ($old as $key => $o) {
-      $n = $new[$key];
-
-      if (!$o || !$n) {
-        continue;
-      }
-
-      if ($is_trailing) {
-        // In "trailing" mode, we need to identify lines which are marked
-        // changed but differ only by trailing whitespace. We mark these lines
-        // unchanged.
-        if ($o['type'] != $n['type']) {
-          if (rtrim($o['text']) === rtrim($n['text'])) {
-            $old[$key]['type'] = null;
-            $new[$key]['type'] = null;
-          }
-        }
-      } else {
-        // In "ignore most" and "ignore all" modes, we need to identify lines
-        // which are marked unchanged but have internal whitespace changes.
-        // We want to ignore leading and trailing whitespace changes only, not
-        // internal whitespace changes (`diff` doesn't have a mode for this, so
-        // we have to fix it here). If the text is marked unchanged but the
-        // old and new text differs by internal space, mark the lines changed.
-        if ($o['type'] === null && $n['type'] === null) {
-          if ($o['text'] !== $n['text']) {
-            if (trim($o['text']) !== trim($n['text'])) {
-              $old[$key]['type'] = '-';
-              $new[$key]['type'] = '+';
-            }
-          }
-        }
-      }
-    }
-
-    $this->setOldLines($old);
-    $this->setNewLines($new);
-
     return $this;
   }
 
diff --git a/src/applications/differential/parser/DifferentialLineAdjustmentMap.php b/src/applications/differential/parser/DifferentialLineAdjustmentMap.php
index fde8f61f7d..e30f2ca866 100644
--- a/src/applications/differential/parser/DifferentialLineAdjustmentMap.php
+++ b/src/applications/differential/parser/DifferentialLineAdjustmentMap.php
@@ -359,7 +359,6 @@ final class DifferentialLineAdjustmentMap extends Phobject {
       }
 
       $changeset = id(new PhabricatorDifferenceEngine())
-        ->setIgnoreWhitespace(true)
         ->generateChangesetFromFileContent($u_old, $v_old);
 
       $results[$u][$v] = self::newFromHunks(
diff --git a/src/applications/differential/render/DifferentialChangesetHTMLRenderer.php b/src/applications/differential/render/DifferentialChangesetHTMLRenderer.php
index 30acc71c88..2e760d99bb 100644
--- a/src/applications/differential/render/DifferentialChangesetHTMLRenderer.php
+++ b/src/applications/differential/render/DifferentialChangesetHTMLRenderer.php
@@ -367,7 +367,6 @@ abstract class DifferentialChangesetHTMLRenderer
     $reference = $this->getRenderingReference();
 
     if ($force !== 'text' &&
-        $force !== 'whitespace' &&
         $force !== 'none' &&
         $force !== 'default') {
       throw new Exception(
@@ -388,10 +387,6 @@ abstract class DifferentialChangesetHTMLRenderer
       'range' => $range,
     );
 
-    if ($force == 'whitespace') {
-      $meta['whitespace'] = DifferentialChangesetParser::WHITESPACE_SHOW_ALL;
-    }
-
     $content = array();
     $content[] = $message;
     if ($force !== 'none') {
diff --git a/src/applications/differential/render/DifferentialChangesetRenderer.php b/src/applications/differential/render/DifferentialChangesetRenderer.php
index c5d033a4a9..866ae15ac9 100644
--- a/src/applications/differential/render/DifferentialChangesetRenderer.php
+++ b/src/applications/differential/render/DifferentialChangesetRenderer.php
@@ -406,9 +406,6 @@ abstract class DifferentialChangesetRenderer extends Phobject {
    *      important (e.g., generated code).
    *    - `"text"`: Force the text to be shown. This is probably only relevant
    *      when a file is not changed.
-   *    - `"whitespace"`: Force the text to be shown, and the diff to be
-   *      rendered with all whitespace shown. This is probably only relevant
-   *      when a file is changed only by altering whitespace.
    *    - `"none"`: Don't show the link (e.g., text not available).
    *
    * @param   string        Message explaining why the diff is hidden.
diff --git a/src/applications/differential/storage/DifferentialChangeset.php b/src/applications/differential/storage/DifferentialChangeset.php
index 00af84bc4e..03400d7a16 100644
--- a/src/applications/differential/storage/DifferentialChangeset.php
+++ b/src/applications/differential/storage/DifferentialChangeset.php
@@ -249,17 +249,6 @@ final class DifferentialChangeset
     return $path;
   }
 
-  public function getWhitespaceMatters() {
-    $config = PhabricatorEnv::getEnvConfig('differential.whitespace-matters');
-    foreach ($config as $regexp) {
-      if (preg_match($regexp, $this->getFilename())) {
-        return true;
-      }
-    }
-
-    return false;
-  }
-
   public function attachDiff(DifferentialDiff $diff) {
     $this->diff = $diff;
     return $this;
diff --git a/src/applications/differential/view/DifferentialChangesetDetailView.php b/src/applications/differential/view/DifferentialChangesetDetailView.php
index cb697c2e9d..211403c8bd 100644
--- a/src/applications/differential/view/DifferentialChangesetDetailView.php
+++ b/src/applications/differential/view/DifferentialChangesetDetailView.php
@@ -9,7 +9,6 @@ final class DifferentialChangesetDetailView extends AphrontView {
   private $id;
   private $vsChangesetID;
   private $renderURI;
-  private $whitespace;
   private $renderingRef;
   private $autoload;
   private $loaded;
@@ -42,15 +41,6 @@ final class DifferentialChangesetDetailView extends AphrontView {
     return $this->renderingRef;
   }
 
-  public function setWhitespace($whitespace) {
-    $this->whitespace = $whitespace;
-    return $this;
-  }
-
-  public function getWhitespace() {
-    return $this->whitespace;
-  }
-
   public function setRenderURI($render_uri) {
     $this->renderURI = $render_uri;
     return $this;
@@ -196,7 +186,6 @@ final class DifferentialChangesetDetailView extends AphrontView {
           'left'  => $left_id,
           'right' => $right_id,
           'renderURI' => $this->getRenderURI(),
-          'whitespace' => $this->getWhitespace(),
           'highlight' => null,
           'renderer' => $this->getRenderer(),
           'ref' => $this->getRenderingRef(),
diff --git a/src/applications/differential/view/DifferentialChangesetListView.php b/src/applications/differential/view/DifferentialChangesetListView.php
index 367991497c..67568005fa 100644
--- a/src/applications/differential/view/DifferentialChangesetListView.php
+++ b/src/applications/differential/view/DifferentialChangesetListView.php
@@ -7,7 +7,6 @@ final class DifferentialChangesetListView extends AphrontView {
   private $references = array();
   private $inlineURI;
   private $renderURI = '/differential/changeset/';
-  private $whitespace;
   private $background;
   private $header;
   private $isStandalone;
@@ -100,11 +99,6 @@ final class DifferentialChangesetListView extends AphrontView {
     return $this;
   }
 
-  public function setWhitespace($whitespace) {
-    $this->whitespace = $whitespace;
-    return $this;
-  }
-
   public function setVsMap(array $vs_map) {
     $this->vsMap = $vs_map;
     return $this;
@@ -180,7 +174,6 @@ final class DifferentialChangesetListView extends AphrontView {
       $detail->setRenderingRef($ref);
 
       $detail->setRenderURI($this->renderURI);
-      $detail->setWhitespace($this->whitespace);
       $detail->setRenderer($renderer);
 
       if ($this->getParser()) {
@@ -352,8 +345,7 @@ final class DifferentialChangesetListView extends AphrontView {
     $meta = array();
 
     $qparams = array(
-      'ref'         => $ref,
-      'whitespace'  => $this->whitespace,
+      'ref' => $ref,
     );
 
     if ($this->standaloneURI) {
diff --git a/src/applications/differential/view/DifferentialRevisionUpdateHistoryView.php b/src/applications/differential/view/DifferentialRevisionUpdateHistoryView.php
index a77b320d82..07ca983bc0 100644
--- a/src/applications/differential/view/DifferentialRevisionUpdateHistoryView.php
+++ b/src/applications/differential/view/DifferentialRevisionUpdateHistoryView.php
@@ -5,7 +5,6 @@ final class DifferentialRevisionUpdateHistoryView extends AphrontView {
   private $diffs = array();
   private $selectedVersusDiffID;
   private $selectedDiffID;
-  private $selectedWhitespace;
   private $commitsForLinks = array();
   private $unitStatus = array();
 
@@ -25,11 +24,6 @@ final class DifferentialRevisionUpdateHistoryView extends AphrontView {
     return $this;
   }
 
-  public function setSelectedWhitespace($whitespace) {
-    $this->selectedWhitespace = $whitespace;
-    return $this;
-  }
-
   public function setCommitsForLinks(array $commits) {
     assert_instances_of($commits, 'PhabricatorRepositoryCommit');
     $this->commitsForLinks = $commits;
@@ -224,28 +218,6 @@ final class DifferentialRevisionUpdateHistoryView extends AphrontView {
         'radios' => $radios,
       ));
 
-    $options = array(
-      DifferentialChangesetParser::WHITESPACE_IGNORE_ALL => pht('Ignore All'),
-      DifferentialChangesetParser::WHITESPACE_IGNORE_MOST => pht('Ignore Most'),
-      DifferentialChangesetParser::WHITESPACE_IGNORE_TRAILING =>
-        pht('Ignore Trailing'),
-      DifferentialChangesetParser::WHITESPACE_SHOW_ALL => pht('Show All'),
-    );
-
-    foreach ($options as $value => $label) {
-      $options[$value] = phutil_tag(
-        'option',
-        array(
-          'value' => $value,
-          'selected' => ($value == $this->selectedWhitespace)
-          ? 'selected'
-          : null,
-        ),
-        $label);
-    }
-    $select = phutil_tag('select', array('name' => 'whitespace'), $options);
-
-
     $table = id(new AphrontTableView($rows));
     $table->setHeaders(
       array(
@@ -291,13 +263,6 @@ final class DifferentialRevisionUpdateHistoryView extends AphrontView {
         'class' => 'differential-update-history-footer',
       ),
       array(
-        phutil_tag(
-          'label',
-          array(),
-          array(
-            pht('Whitespace Changes:'),
-            $select,
-          )),
         phutil_tag(
           'button',
           array(),
diff --git a/src/applications/diffusion/controller/DiffusionChangeController.php b/src/applications/diffusion/controller/DiffusionChangeController.php
index 90258134c4..0120c978d0 100644
--- a/src/applications/diffusion/controller/DiffusionChangeController.php
+++ b/src/applications/diffusion/controller/DiffusionChangeController.php
@@ -64,9 +64,6 @@ final class DiffusionChangeController extends DiffusionController {
     $changeset_view->setRawFileURIs($left_uri, $right_uri);
 
     $changeset_view->setRenderURI($repository->getPathURI('diff/'));
-
-    $changeset_view->setWhitespace(
-      DifferentialChangesetParser::WHITESPACE_SHOW_ALL);
     $changeset_view->setUser($viewer);
     $changeset_view->setHeader($changeset_header);
 
diff --git a/src/applications/diffusion/controller/DiffusionDiffController.php b/src/applications/diffusion/controller/DiffusionDiffController.php
index 86409c6faa..a0111d001f 100644
--- a/src/applications/diffusion/controller/DiffusionDiffController.php
+++ b/src/applications/diffusion/controller/DiffusionDiffController.php
@@ -88,9 +88,6 @@ final class DiffusionDiffController extends DiffusionController {
       ($viewer->getPHID() == $commit->getAuthorPHID()));
     $parser->setObjectOwnerPHID($commit->getAuthorPHID());
 
-    $parser->setWhitespaceMode(
-      DifferentialChangesetParser::WHITESPACE_SHOW_ALL);
-
     $inlines = PhabricatorAuditInlineComment::loadDraftAndPublishedComments(
       $viewer,
       $commit->getPHID(),
diff --git a/src/docs/user/userguide/differential_faq.diviner b/src/docs/user/userguide/differential_faq.diviner
index aea49c4ce6..0df1f7b1c9 100644
--- a/src/docs/user/userguide/differential_faq.diviner
+++ b/src/docs/user/userguide/differential_faq.diviner
@@ -51,22 +51,6 @@ You need to install and configure **Pygments** to highlight anything else than
 PHP. See the `pygments.enabled` configuration setting.
 
 
-= What do the whitespace options mean? =
-
-Most of these are pretty straightforward, but "Ignore Most" is not:
-
-  - **Show All**: Show all whitespace.
-  - **Ignore Trailing**: Ignore changes which only affect trailing whitespace.
-  - **Ignore Most**: Ignore changes which only affect leading or trailing
-    whitespace (but not whitespace changes between non-whitespace characters)
-    in files which are not marked as having significant whitespace.
-    In those files, show whitespace changes. By default, Python (.py) and
-    Haskell (.lhs, .hs) are marked as having significant whitespace, but this
-    can be changed in the `differential.whitespace-matters` configuration
-    setting.
-  - **Ignore All**: Ignore all whitespace changes in all files.
-
-
 = What do the very light green and red backgrounds mean? =
 
 Differential uses these colors to mark changes coming from rebase: they are
diff --git a/src/infrastructure/diff/PhabricatorDifferenceEngine.php b/src/infrastructure/diff/PhabricatorDifferenceEngine.php
index 3b4eb55473..90f1d9b10e 100644
--- a/src/infrastructure/diff/PhabricatorDifferenceEngine.php
+++ b/src/infrastructure/diff/PhabricatorDifferenceEngine.php
@@ -10,7 +10,6 @@
 final class PhabricatorDifferenceEngine extends Phobject {
 
 
-  private $ignoreWhitespace;
   private $oldName;
   private $newName;
 
@@ -18,19 +17,6 @@ final class PhabricatorDifferenceEngine extends Phobject {
 /* -(  Configuring the Engine  )--------------------------------------------- */
 
 
-  /**
-   * If true, ignore whitespace when computing differences.
-   *
-   * @param bool Ignore whitespace?
-   * @return this
-   * @task config
-   */
-  public function setIgnoreWhitespace($ignore_whitespace) {
-    $this->ignoreWhitespace = $ignore_whitespace;
-    return $this;
-  }
-
-
   /**
    * Set the name to identify the old file with. Primarily cosmetic.
    *
@@ -73,9 +59,6 @@ final class PhabricatorDifferenceEngine extends Phobject {
   public function generateRawDiffFromFileContent($old, $new) {
 
     $options = array();
-    if ($this->ignoreWhitespace) {
-      $options[] = '-bw';
-    }
 
     // Generate diffs with full context.
     $options[] = '-U65535';
@@ -100,12 +83,10 @@ final class PhabricatorDifferenceEngine extends Phobject {
       $new_tmp);
 
     if (!$err) {
-      // This indicates that the two files are the same (or, possibly, the
-      // same modulo whitespace differences, which is why we can't do this
-      // check trivially before running `diff`). Build a synthetic, changeless
-      // diff so that we can still render the raw, unchanged file instead of
-      // being forced to just say "this file didn't change" since we don't have
-      // the content.
+      // This indicates that the two files are the same. Build a synthetic,
+      // changeless diff so that we can still render the raw, unchanged file
+      // instead of being forced to just say "this file didn't change" since we
+      // don't have the content.
 
       $entire_file = explode("\n", $old);
       foreach ($entire_file as $k => $line) {
@@ -123,26 +104,6 @@ final class PhabricatorDifferenceEngine extends Phobject {
               "+++ {$new_name}\n".
               "@@ -1,{$len} +1,{$len} @@\n".
               $entire_file."\n";
-    } else {
-      if ($this->ignoreWhitespace) {
-
-        // Under "-bw", `diff` is inconsistent about emitting "\ No newline
-        // at end of file". For instance, a long file with a change in the
-        // middle will emit a contextless "\ No newline..." at the end if a
-        // newline is removed, but not if one is added. A file with a change
-        // at the end will emit the "old" "\ No newline..." block only, even
-        // if the newline was not removed. Since we're ostensibly ignoring
-        // whitespace changes, just drop these lines if they appear anywhere
-        // in the diff.
-
-        $lines = explode("\n", $diff);
-        foreach ($lines as $key => $line) {
-          if (isset($line[0]) && $line[0] == '\\') {
-            unset($lines[$key]);
-          }
-        }
-        $diff = implode("\n", $lines);
-      }
     }
 
     return $diff;
diff --git a/webroot/rsrc/js/application/diff/DiffChangeset.js b/webroot/rsrc/js/application/diff/DiffChangeset.js
index 24d734573d..754f3b16e4 100644
--- a/webroot/rsrc/js/application/diff/DiffChangeset.js
+++ b/webroot/rsrc/js/application/diff/DiffChangeset.js
@@ -22,7 +22,6 @@ JX.install('DiffChangeset', {
 
     this._renderURI = data.renderURI;
     this._ref = data.ref;
-    this._whitespace = data.whitespace;
     this._renderer = data.renderer;
     this._highlight = data.highlight;
     this._encoding = data.encoding;
@@ -46,7 +45,6 @@ JX.install('DiffChangeset', {
 
     _renderURI: null,
     _ref: null,
-    _whitespace: null,
     _renderer: null,
     _highlight: null,
     _encoding: null,
@@ -310,7 +308,6 @@ JX.install('DiffChangeset', {
     _getViewParameters: function() {
       return {
         ref: this._ref,
-        whitespace: this._whitespace || '',
         renderer: this.getRenderer() || '',
         highlight: this._highlight || '',
         encoding: this._encoding || ''