Hype StackHypeStack

Diff checker.

Paste the old version and the new one. Changed lines and the words inside them light up as you type, and nothing leaves your browser.

  • Free
  • No signup
  • Runs in your browser
  • +3 added
  • -3 removed
  • 4 unchanged
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export function greet(name) {
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export function greet(name: string): string {
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const message = "Hello, " + name;
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const message = `Hello, ${name}!`;
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console.log(message);
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return message;
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return message;
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}
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}
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greet("Hype Stack");
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greet("World");
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greet("World");

How it works.

  1. 1

    Paste the original text on the left and the changed version on the right.

  2. 2

    Pick side by side or unified, and ignore whitespace or case if those changes are noise.

  3. 3

    Read the highlights, or copy the diff with + and - markers to share it.

How the text compare works

Both texts are split into lines, and the longest run of lines they share is found first. Everything outside that run is an added or a removed line. Same idea as git diff, the Myers algorithm.

When a removed line sits right where a new one was added, the two are paired as an edit and compared again word by word. That's why a one-word change in a long line shows as one highlighted word, not two walls of red and green.

When to ignore whitespace or case

Turn on Ignore whitespace when one version was reformatted: re-indented code, trailing spaces, tabs swapped for spaces. Lines that only differ in spacing then count as unchanged.

Ignore case helps with SQL keywords, headings that changed style, or anything pasted from a tool that shouts in capitals. Each side still shows its own original text.

Questions, answered.

How do I compare two texts for differences?

Paste the first text into Original text and the second into Changed text. The diff appears below right away, with added lines in green, removed lines in red, and the changed words inside each line highlighted.

Is my text uploaded anywhere?

No. The comparison runs in your browser, so it's fine for code, contracts or config files with secrets in them. Nothing is sent or stored.

What's the difference between side by side and unified view?

Side by side puts the old text on the left and the new one on the right, line for line. Unified shows one column, removed lines first and added lines after, like a git diff or a pull request.

Can I compare code with this diff checker?

Yes. It works on any plain text: source code, JSON, YAML, SQL, Markdown or prose. For JSON where key order should not matter, use the JSON diff tool instead.

How big can the texts be?

Tens of thousands of lines compare in well under a second. Two very large texts that share almost nothing can take longer, and the tool tells you to compare a smaller section instead of freezing the tab.

More free tools.

All tools

Every change your AI makes, in a diff.

Add a blog post announcing the launch, written in MDX.. Translate the whole app into Spanish and German.. Send a welcome email when someone signs up.

Hype Stack is a free starter that lives in your own repo, and paid packs install as source files, not a package. So every change shows up in git, line by line.

See how Hype Stack works