🩹 Unified Diff & Apply-Patch Workbench

Parse, preview, and apply unified diffs locally with exact conflict evidence.

Runs locally in your browser. Supply a JSON object mapping file paths to their current text, then preview before applying.

Need a bounded metadata-only review artifact? Use the Context Workbench Patch Verification Pack; repository reads, patch bodies, and source text stay out of the pack.

Source files (JSON map)

{"alpha.txt":"one\ntwo\nthree\n"}

Unified diff

--- a/alpha.txt
+++ b/alpha.txt
@@ -1,3 +1,3 @@
 one
-two
+TWO
 three

Result

Metadata-only Patch Verification report

Runs in your browser

Runs locally in your browser; no filesystem access or server upload.

Include current input in shared/debug payload

What this tool does

Parses standard unified diffs, previews every file and hunk, and applies patches only when supplied source lines match exactly.

Why it is useful

Exact context matching prevents a patch from drifting onto similar-looking text.

Typed failures

MALFORMED_PATCH identifies invalid patch syntax. PATCH_CONFLICT reports the exact file, hunk, source line, expected text, and actual text.

Privacy note

Runs locally in your browser. No source text, patch, or output is uploaded.

Important limitation

This workbench operates on text you supply. It never reads from or writes to your filesystem.

View all in Developer →