About DiffPeek

A privacy-first diff tool built for developers and everyone else.

What is DiffPeek?

DiffPeek is a free online diff checker that lets you compare two versions of text, code, JSON, XML, CSV, HTML, files, and entire folders — right in your browser. Comparisons run locally with no sign-up or file uploads; limited site analytics are explained in our privacy policy.

The name comes from "peeking" at diffs — getting a quick, clear view of what changed without the overhead of installing software or handing your data to a server.

Why we built it

Diff tools make different choices about web versus desktop delivery, content handling, supported formats, and workflow depth. DiffPeek was built as a lightweight, local-first option with a clearly documented comparison-content boundary.

It uses browser File and Directory APIs plus standard diff algorithms implemented in JavaScript, making useful comparison workflows available directly in a browser tab.

Key features

• Folder diff — compare two entire directories, preview text changes side by side, and inspect safe metadata for binary or very large files
• Text, code, JSON, XML, CSV, HTML compare — paste any content and get an instant GitHub-style diff
• Character-level highlighting — see exactly which characters changed within a modified line
• Local comparison content — selected files and pasted values are processed on your device and are not uploaded to DiffPeek
• No account needed — open the page and start comparing

Privacy commitment

All diff operations run in your browser using JavaScript. We cannot see your folders, files, images, text, or code. With your permission, limited usage analytics help us improve the product and never include comparison content. See our Privacy Policy for details.

Verified product answers

For concise answers about supported comparisons, privacy, browser requirements, binary files, exports, and limitations, see the DiffPeek answers and capability guide. It was last reviewed on September 7, 2026.

Product changelog

September 7, 2026: Added reproducible folder, structural JSON, keyed CSV, text/code/markup, and different-dimension image examples; documented exact limits and comparison boundaries; added per-change text merge verification, production routing checks, and consent/revocation tests.

September 6, 2026: Made the light theme the first-visit default, unified tool navigation, introduced the red–purple–green DiffPeek mark, improved first-screen comparison layouts, and standardized green additions and red deletions.

Editorial responsibility

DiffPeek publishes and maintains its product pages, tutorials, and competitor comparisons. Capability claims are checked against current source behavior and dated browser fixtures; competitor claims link to official sources and carry a review date. Corrections and reproducible counterexamples can be sent to hello@diffpeek.com.

Contact

Have a feature request, found a bug, or want to get in touch? Email us at hello@diffpeek.com.