diff --git a/scm-ui/ui-components/.storybook/webpack.config.js b/scm-ui/ui-components/.storybook/webpack.config.js
index 947515f4d3..c8459adf6b 100644
--- a/scm-ui/ui-components/.storybook/webpack.config.js
+++ b/scm-ui/ui-components/.storybook/webpack.config.js
@@ -20,6 +20,10 @@ module.exports = {
           }
         ]
       },
+      {
+        test: /\.worker\.(j|t)s$/,
+        use: { loader: "worker-loader" }
+      },
       {
         test: /\.(css|scss|sass)$/i,
         use: [
@@ -38,8 +42,6 @@ module.exports = {
     ]
   },
   resolve: {
-    extensions: [
-      ".ts", ".tsx", ".js", ".jsx", ".css", ".scss", ".json"
-    ]
+    extensions: [".ts", ".tsx", ".js", ".jsx", ".css", ".scss", ".json"]
   }
 };
diff --git a/scm-ui/ui-components/package.json b/scm-ui/ui-components/package.json
index 1e3648dbab..d8d4820174 100644
--- a/scm-ui/ui-components/package.json
+++ b/scm-ui/ui-components/package.json
@@ -26,6 +26,7 @@
     "@types/enzyme": "^3.10.3",
     "@types/fetch-mock": "^7.3.1",
     "@types/jest": "^24.0.19",
+    "@types/lowlight": "^0.0.0",
     "@types/query-string": "5",
     "@types/react": "^16.9.9",
     "@types/react-dom": "^16.9.2",
@@ -40,7 +41,8 @@
     "raf": "^3.4.0",
     "react-test-renderer": "^16.10.2",
     "storybook-addon-i18next": "^1.2.1",
-    "typescript": "^3.7.2"
+    "typescript": "^3.7.2",
+    "worker-loader": "^2.0.0"
   },
   "dependencies": {
     "@scm-manager/ui-extensions": "^2.0.0-SNAPSHOT",
@@ -48,6 +50,8 @@
     "classnames": "^2.2.6",
     "date-fns": "^2.4.1",
     "event-source-polyfill": "^1.0.9",
+    "gitdiff-parser": "^0.1.2",
+    "lowlight": "^1.13.0",
     "query-string": "5",
     "react": "^16.8.6",
     "react-diff-view": "^2.4.1",
@@ -56,8 +60,7 @@
     "react-markdown": "^4.0.6",
     "react-router-dom": "^5.1.2",
     "react-select": "^2.1.2",
-    "react-syntax-highlighter": "^11.0.2",
-    "gitdiff-parser": "^0.1.2"
+    "react-syntax-highlighter": "^11.0.2"
   },
   "babel": {
     "presets": [
diff --git a/scm-ui/ui-components/src/repos/Diff.stories.tsx b/scm-ui/ui-components/src/repos/Diff.stories.tsx
index 1b38f362d3..149b1ecab5 100644
--- a/scm-ui/ui-components/src/repos/Diff.stories.tsx
+++ b/scm-ui/ui-components/src/repos/Diff.stories.tsx
@@ -7,8 +7,9 @@ import simpleDiff from "../__resources__/Diff.simple";
 import hunksDiff from "../__resources__/Diff.hunks";
 import binaryDiff from "../__resources__/Diff.binary";
 import Button from "../buttons/Button";
-import { DiffEventContext } from "./DiffTypes";
+import { DiffEventContext, File } from "./DiffTypes";
 import Toast from "../toast/Toast";
+import { getPath } from "./diffs";
 
 const diffFiles = parser.parse(simpleDiff);
 
@@ -57,4 +58,16 @@ storiesOf("Diff", module)
   .add("Binaries", () => {
     const binaryDiffFiles = parser.parse(binaryDiff);
     return <Diff diff={binaryDiffFiles} />;
+  })
+  .add("SyntaxHighlighting", () => {
+    const filesWithLanguage = diffFiles.map((file: File) => {
+      const ext = getPath(file).split(".")[1];
+      if (ext === "tsx") {
+        file.language = "typescript";
+      } else {
+        file.language = ext;
+      }
+      return file;
+    });
+    return <Diff diff={filesWithLanguage} />;
   });
diff --git a/scm-ui/ui-components/src/repos/DiffFile.tsx b/scm-ui/ui-components/src/repos/DiffFile.tsx
index 49da9b2484..47b10997cc 100644
--- a/scm-ui/ui-components/src/repos/DiffFile.tsx
+++ b/scm-ui/ui-components/src/repos/DiffFile.tsx
@@ -3,11 +3,12 @@ import { withTranslation, WithTranslation } from "react-i18next";
 import classNames from "classnames";
 import styled from "styled-components";
 // @ts-ignore
-import { Diff as DiffComponent, getChangeKey, Hunk, Decoration } from "react-diff-view";
+import { getChangeKey, Hunk, Decoration } from "react-diff-view";
 import { Button, ButtonGroup } from "../buttons";
 import Tag from "../Tag";
 import Icon from "../Icon";
 import { ChangeEvent, Change, File, Hunk as HunkType, DiffObjectProps } from "./DiffTypes";
+import TokenizedDiffView from "./TokenizedDiffView";
 
 const EMPTY_ANNOTATION_FACTORY = {};
 
@@ -57,33 +58,6 @@ const ChangeTypeTag = styled(Tag)`
   margin-left: 0.75rem;
 `;
 
-const ModifiedDiffComponent = styled(DiffComponent)`
-  /* align line numbers */
-  & .diff-gutter {
-    text-align: right;
-  }
-  /* column sizing */
-  > colgroup .diff-gutter-col {
-    width: 3.25rem;
-  }
-  /* prevent following content from moving down */
-  > .diff-gutter:empty:hover::after {
-    font-size: 0.7rem;
-  }
-  /* smaller font size for code */
-  & .diff-line {
-    font-size: 0.75rem;
-  }
-  /* comment padding for sidebyside view */
-  &.split .diff-widget-content .is-indented-line {
-    padding-left: 3.25rem;
-  }
-  /* comment padding for combined view */
-  &.unified .diff-widget-content .is-indented-line {
-    padding-left: 6.5rem;
-  }
-`;
-
 class DiffFile extends React.Component<Props, State> {
   static defaultProps: Partial<Props> = {
     defaultCollapse: false,
@@ -264,9 +238,9 @@ class DiffFile extends React.Component<Props, State> {
       body = (
         <div className="panel-block is-paddingless">
           {fileAnnotations}
-          <ModifiedDiffComponent className={viewType} viewType={viewType} hunks={file.hunks} diffType={file.type}>
+          <TokenizedDiffView className={viewType} viewType={viewType} file={file}>
             {(hunks: HunkType[]) => this.concat(hunks.map(this.renderHunk))}
-          </ModifiedDiffComponent>
+          </TokenizedDiffView>
         </div>
       );
     }
diff --git a/scm-ui/ui-components/src/repos/DiffTypes.ts b/scm-ui/ui-components/src/repos/DiffTypes.ts
index 49e9785d29..813322529e 100644
--- a/scm-ui/ui-components/src/repos/DiffTypes.ts
+++ b/scm-ui/ui-components/src/repos/DiffTypes.ts
@@ -18,6 +18,7 @@ export type File = {
   oldPath: string;
   oldRevision?: string;
   type: FileChangeType;
+  language?: string;
   // TODO does this property exists?
   isBinary?: boolean;
 };
diff --git a/scm-ui/ui-components/src/repos/Tokenize.worker.ts b/scm-ui/ui-components/src/repos/Tokenize.worker.ts
new file mode 100644
index 0000000000..d64df14c11
--- /dev/null
+++ b/scm-ui/ui-components/src/repos/Tokenize.worker.ts
@@ -0,0 +1,29 @@
+/* eslint-disable no-restricted-globals */
+// @ts-ignore we have no types for react-diff-view
+import { tokenize } from "react-diff-view";
+import refractor from "./refractorAdapter";
+
+self.addEventListener("message", ({ data: { id, payload } }) => {
+  const { hunks, language } = payload;
+  const options = {
+    highlight: language !== "text",
+    language: language,
+    refractor
+  };
+  try {
+    const tokens = tokenize(hunks, options);
+    const payload = {
+      success: true,
+      tokens: tokens
+    };
+    // @ts-ignore seems to use wrong typing
+    self.postMessage({ id, payload });
+  } catch (ex) {
+    const payload = {
+      success: false,
+      reason: ex.message
+    };
+    // @ts-ignore seems to use wrong typing
+    self.postMessage({ id, payload });
+  }
+});
diff --git a/scm-ui/ui-components/src/repos/TokenizedDiffView.tsx b/scm-ui/ui-components/src/repos/TokenizedDiffView.tsx
new file mode 100644
index 0000000000..fcc3397cb8
--- /dev/null
+++ b/scm-ui/ui-components/src/repos/TokenizedDiffView.tsx
@@ -0,0 +1,62 @@
+import React, { FC } from "react";
+import styled from "styled-components";
+// @ts-ignore we have no typings for react-diff-view
+import { Diff, useTokenizeWorker } from "react-diff-view";
+// @ts-ignore we use webpack worker-loader to load the web worker
+import TokenizeWorker from "./Tokenize.worker";
+import { File } from "./DiffTypes";
+
+// styling for the diff tokens
+// this must be aligned with th style, which is used in the SyntaxHighlighter component
+import "highlight.js/styles/arduino-light.css";
+
+const DiffView = styled(Diff)`
+  /* align line numbers */
+  & .diff-gutter {
+    text-align: right;
+  }
+  /* column sizing */
+  > colgroup .diff-gutter-col {
+    width: 3.25rem;
+  }
+  /* prevent following content from moving down */
+  > .diff-gutter:empty:hover::after {
+    font-size: 0.7rem;
+  }
+  /* smaller font size for code */
+  & .diff-line {
+    font-size: 0.75rem;
+  }
+  /* comment padding for sidebyside view */
+  &.split .diff-widget-content .is-indented-line {
+    padding-left: 3.25rem;
+  }
+  /* comment padding for combined view */
+  &.unified .diff-widget-content .is-indented-line {
+    padding-left: 6.5rem;
+  }
+`;
+
+// WebWorker which creates tokens for syntax highlighting
+const tokenize = new TokenizeWorker();
+
+type Props = {
+  file: File;
+  viewType: "split" | "unified";
+  className?: string;
+};
+
+const TokenizedDiffView: FC<Props> = ({ file, viewType, className, children }) => {
+  const { tokens } = useTokenizeWorker(tokenize, {
+    hunks: file.hunks,
+    language: file.language || "text"
+  });
+
+  return (
+    <DiffView className={className} viewType={viewType} tokens={tokens} hunks={file.hunks} diffType={file.type}>
+      {children}
+    </DiffView>
+  );
+};
+
+export default TokenizedDiffView;
diff --git a/scm-ui/ui-components/src/repos/refractorAdapter.ts b/scm-ui/ui-components/src/repos/refractorAdapter.ts
new file mode 100644
index 0000000000..3e0425aad8
--- /dev/null
+++ b/scm-ui/ui-components/src/repos/refractorAdapter.ts
@@ -0,0 +1,14 @@
+import lowlight from "lowlight";
+
+// adapter to let lowlight look like refractor
+// this is required because react-diff-view does only support refractor,
+// but we want same highlighting as in the source code browser.
+
+const refractorAdapter = {
+  ...lowlight,
+  highlight: (value: string, language: string) => {
+    return lowlight.highlight(language, value).value;
+  }
+};
+
+export default refractorAdapter;
diff --git a/scm-ui/ui-scripts/package.json b/scm-ui/ui-scripts/package.json
index 4b2564b419..c53d2eff98 100644
--- a/scm-ui/ui-scripts/package.json
+++ b/scm-ui/ui-scripts/package.json
@@ -24,6 +24,7 @@
     "script-loader": "^0.7.2",
     "style-loader": "^1.0.0",
     "thread-loader": "^2.1.3",
+    "worker-loader": "^2.0.0",
     "webpack": "^4.41.5",
     "webpack-cli": "^3.3.10",
     "webpack-dev-server": "^3.10.1"
diff --git a/scm-ui/ui-scripts/src/webpack.config.js b/scm-ui/ui-scripts/src/webpack.config.js
index b4c32fc680..5c8595e505 100644
--- a/scm-ui/ui-scripts/src/webpack.config.js
+++ b/scm-ui/ui-scripts/src/webpack.config.js
@@ -30,6 +30,10 @@ module.exports = [
             systemjs: false
           }
         },
+        {
+          test: /\.worker\.(j|t)s$/,
+          use: { loader: "worker-loader" }
+        },
         {
           test: /\.(js|ts|jsx|tsx)$/i,
           exclude: /node_modules/,
diff --git a/yarn.lock b/yarn.lock
index ef120d73f6..1594f5a8ba 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2758,6 +2758,11 @@
   resolved "https://registry.yarnpkg.com/@types/lodash/-/lodash-4.14.149.tgz#1342d63d948c6062838fbf961012f74d4e638440"
   integrity sha512-ijGqzZt/b7BfzcK9vTrS6MFljQRPn5BFWOx8oE0GYxribu6uV+aA9zZuXI1zc/etK9E8nrgdoF2+LgUw7+9tJQ==
 
+"@types/lowlight@^0.0.0":
+  version "0.0.0"
+  resolved "https://registry.yarnpkg.com/@types/lowlight/-/lowlight-0.0.0.tgz#eef9ff807ff29bbf9f2fe55d0488fb9fc9d89df6"
+  integrity sha1-7vn/gH/ym7+fL+VdBIj7n8nYnfY=
+
 "@types/minimatch@*":
   version "3.0.3"
   resolved "https://registry.yarnpkg.com/@types/minimatch/-/minimatch-3.0.3.tgz#3dca0e3f33b200fc7d1139c0cd96c1268cadfd9d"
@@ -7672,6 +7677,11 @@ highlight.js@~9.13.0:
   resolved "https://registry.yarnpkg.com/highlight.js/-/highlight.js-9.13.1.tgz#054586d53a6863311168488a0f58d6c505ce641e"
   integrity sha512-Sc28JNQNDzaH6PORtRLMvif9RSn1mYuOoX3omVjnb0+HbpPygU2ALBI0R/wsiqCb4/fcp07Gdo8g+fhtFrQl6A==
 
+highlight.js@~9.16.0:
+  version "9.16.2"
+  resolved "https://registry.yarnpkg.com/highlight.js/-/highlight.js-9.16.2.tgz#68368d039ffe1c6211bcc07e483daf95de3e403e"
+  integrity sha512-feMUrVLZvjy0oC7FVJQcSQRqbBq9kwqnYE4+Kj9ZjbHh3g+BisiPgF49NyQbVLNdrL/qqZr3Ca9yOKwgn2i/tw==
+
 history@^4.10.1, history@^4.9.0:
   version "4.10.1"
   resolved "https://registry.yarnpkg.com/history/-/history-4.10.1.tgz#33371a65e3a83b267434e2b3f3b1b4c58aad4cf3"
@@ -9435,7 +9445,7 @@ loader-runner@^2.3.1, loader-runner@^2.4.0:
   resolved "https://registry.yarnpkg.com/loader-runner/-/loader-runner-2.4.0.tgz#ed47066bfe534d7e84c4c7b9998c2a75607d9357"
   integrity sha512-Jsmr89RcXGIwivFY21FcRrisYZfvLMTWx5kOLc+JTxtpBOG6xML0vzbc6SEQG2FO9/4Fc3wW4LVcB5DmGflaRw==
 
-loader-utils@1.2.3, loader-utils@^1.0.2, loader-utils@^1.1.0, loader-utils@^1.2.3:
+loader-utils@1.2.3, loader-utils@^1.0.0, loader-utils@^1.0.2, loader-utils@^1.1.0, loader-utils@^1.2.3:
   version "1.2.3"
   resolved "https://registry.yarnpkg.com/loader-utils/-/loader-utils-1.2.3.tgz#1ff5dc6911c9f0a062531a4c04b609406108c2c7"
   integrity sha512-fkpz8ejdnEMG3s37wGL07iSBDg99O9D5yflE9RGNH3hRdx9SOwYfnGYdZOUIZitN8E+E2vkq3MUMYMvPYl5ZZA==
@@ -9602,6 +9612,14 @@ lower-case@^1.1.1:
   resolved "https://registry.yarnpkg.com/lower-case/-/lower-case-1.1.4.tgz#9a2cabd1b9e8e0ae993a4bf7d5875c39c42e8eac"
   integrity sha1-miyr0bno4K6ZOkv31YdcOcQujqw=
 
+lowlight@^1.13.0:
+  version "1.13.0"
+  resolved "https://registry.yarnpkg.com/lowlight/-/lowlight-1.13.0.tgz#9b4fd00559985e40e11c916ccab14c7c0cf4320d"
+  integrity sha512-bFXLa+UO1eM3zieFAcNqf6rTQ1D5ERFv64/euQbbH/LT3U9XXwH6tOrgUAGWDsQ1QgN3ZhgOcv8p3/S+qKGdTQ==
+  dependencies:
+    fault "^1.0.2"
+    highlight.js "~9.16.0"
+
 lowlight@~1.11.0:
   version "1.11.0"
   resolved "https://registry.yarnpkg.com/lowlight/-/lowlight-1.11.0.tgz#1304d83005126d4e8b1dc0f07981e9b689ec2efc"
@@ -12989,6 +13007,14 @@ scheduler@^0.18.0:
     loose-envify "^1.1.0"
     object-assign "^4.1.1"
 
+schema-utils@^0.4.0:
+  version "0.4.7"
+  resolved "https://registry.yarnpkg.com/schema-utils/-/schema-utils-0.4.7.tgz#ba74f597d2be2ea880131746ee17d0a093c68187"
+  integrity sha512-v/iwU6wvwGK8HbU9yi3/nhGzP0yGSuhQMzL6ySiec1FSrZZDkhm4noOSWzrNFo/jEc+SJY6jRTwuwbSXJPDUnQ==
+  dependencies:
+    ajv "^6.1.0"
+    ajv-keywords "^3.1.0"
+
 schema-utils@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/schema-utils/-/schema-utils-1.0.0.tgz#0b79a93204d7b600d4b2850d1f66c2a34951c770"
@@ -14972,6 +14998,14 @@ worker-farm@^1.7.0:
   dependencies:
     errno "~0.1.7"
 
+worker-loader@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/worker-loader/-/worker-loader-2.0.0.tgz#45fda3ef76aca815771a89107399ee4119b430ac"
+  integrity sha512-tnvNp4K3KQOpfRnD20m8xltE3eWh89Ye+5oj7wXEEHKac1P4oZ6p9oTj8/8ExqoSBnk9nu5Pr4nKfQ1hn2APJw==
+  dependencies:
+    loader-utils "^1.0.0"
+    schema-utils "^0.4.0"
+
 worker-rpc@^0.1.0:
   version "0.1.1"
   resolved "https://registry.yarnpkg.com/worker-rpc/-/worker-rpc-0.1.1.tgz#cb565bd6d7071a8f16660686051e969ad32f54d5"