Diff checker for line-level changes
Compare an original and changed version with a line-level longest-common-subsequence diff that keeps inserted and removed blocks aligned.
This is the free version
Works where you write
PromptDC rewrites selected text in any app, every browser, your IDE and your terminal on Mac and Windows.
One keyboard shortcut
Select text, press Cmd+Shift+E or Ctrl+Shift+E, review the result, then Replace or Copy. It never presses Enter for you.
Your profiles, your models
Pick a default profile per app, or bring your own API key on the Lifetime plan.
Free here: unlimited, this utility runs entirely in your browser. In the app: from $9/mo, or Lifetime from $69 with your own API key.
Simple row-by-row comparison becomes misleading as soon as one version inserts a line, because every later row appears changed. This checker computes a real longest common subsequence, then marks additions in green, removals in red, and shared lines neutrally. Summary counts describe the resulting edit sequence without claiming that moved or rewritten lines are semantically identical. Both texts remain in the browser, and comparisons are unlimited.
Common questions
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Enhance any text you select in any app on desktop, in browsers, in your editor or terminals.
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