Text Diff Checker

Compare two texts line-by-line with additions and removals highlighted.

+3 added2 removed
Version 1 of the prompt.
Be concise.
+Version 2 of the prompt.
+Be concise and factual.
Answer in JSON.
+Include sources.
Runs entirely in your browser — nothing you paste is sent to a server.

About this tool

A line-level diff for prompts, configs, and prose. Uses an LCS algorithm to show the minimum set of additions and deletions — the same approach as git diff.

How it works

  1. Paste the original into the left box and the changed version into the right.
  2. The diff is rendered below with additions in green and removals in red.
  3. Additions/removals are counted at the top.

When to use it

  • Comparing two versions of a system prompt during eval.
  • Diffing two YAML configs before deployment.
  • Reviewing an LLM's edits to a draft.

FAQs

Related resources