diff --git a/README.md b/README.md
index 5575856..3de1132 100644
--- a/README.md
+++ b/README.md
@@ -67,6 +67,7 @@ The HTML output accepts a Javascript object with configuration. Possible options
   - `showFiles`: show a file list before the diff: `true` or `false`, default is `false`
   - `matching`: matching level: `'lines'` for matching lines, `'words'` for matching lines and words or `'none'`, default is `none`
   - `matchWordsThreshold`: similarity threshold for word matching, default is 0.25
+  - `matchingMaxComparisons`: perform at most this much comparisons for line matching a block of changes, default is `2500`
 
 ## Diff2HtmlUI Helper
 
diff --git a/src/line-by-line-printer.js b/src/line-by-line-printer.js
index 01059c4..88130ca 100644
--- a/src/line-by-line-printer.js
+++ b/src/line-by-line-printer.js
@@ -66,7 +66,10 @@
         var insertType;
         var deleteType;
 
-        var doMatching = that.config.matching === 'lines' || that.config.matching === 'words';
+        var comparisons = oldLines.length * newLines.length;
+        var maxComparisons = that.config.matchingMaxComparisons || 2500;
+        var doMatching = comparisons < maxComparisons && (that.config.matching === 'lines' ||
+            that.config.matching === 'words');
 
         if (doMatching) {
           matches = matcher(oldLines, newLines);
diff --git a/src/side-by-side-printer.js b/src/side-by-side-printer.js
index 6d4dbbe..fbf2360 100644
--- a/src/side-by-side-printer.js
+++ b/src/side-by-side-printer.js
@@ -105,7 +105,11 @@
         var matches;
         var insertType;
         var deleteType;
-        var doMatching = that.config.matching === 'lines' || that.config.matching === 'words';
+
+        var comparisons = oldLines.length * newLines.length;
+        var maxComparisons = that.config.matchingMaxComparisons || 2500;
+        var doMatching = comparisons < maxComparisons && (that.config.matching === 'lines' ||
+            that.config.matching === 'words');
 
         if (doMatching) {
           matches = matcher(oldLines, newLines);