Diff two JSON documents with path-level change listing — spot breaking API changes instantly. Review a 500-line response diff in minutes — local processing, free, no signup.
Content reviewed October 2026 · About Toolzum
Compare two OpenAPI specs side-by-side to detect breaking changes, new endpoints, removed fields, and modified schemas between versions.
Decode Base64 strings and pretty-print JSON data — paste encoded text to see the decoded result instantly. Inspect API payloads and tokens readably — free, local, no signup.
Format TypeScript with correct indentation, type-annotation spacing, and interface alignment. Clean up 500-line components before review — local processing, free, no signup.
Diff two PDFs side by side — spot changed clauses, figures, and pages before signing. Review a 20-page contract revision in minutes — local PDF.js comparison, free, no signup.
Sort text lines A–Z, Z–A, by length, or shuffle randomly with duplicate control. Organize 500-line lists instantly — local processing, free, no signup.
Diff old vs new response: removed fields and type changes break clients, added optional fields don't. Review the path list before approving the backend deploy.
Ignored by default — JSON objects are unordered, so reordered keys aren't changes. Enable strict order mode only for canonical-form checks.
Thousand-line payloads diff fine locally; collapse unchanged regions to focus. Save both versions for the PR record.
No — diffing runs locally in your browser. Payloads never leave your device.
With the defaults ({"a":1,"b":2} vs {"a":1,"b":3}) the output is exactly 2 lines: `- b: 2` then `+ b: 3`. Nested objects recurse with dot-joined paths, array elements get [i] suffixes, unparseable input toasts Invalid JSON in one or both inputs, and identical docs print (no differences).
Diff Checker
Compares two input texts side-by-side, highlighting inserted, deleted, and changed lines with distinct background colors. Code never leaves your device — formatting and validation run locally in your browser.
JSON Tree Viewer
Visualize JSON structure as an indented tree — see nested objects and arrays at a glance. Collapse deep branches to navigate large payloads — free, local, no signup.