About Compare Text
Compare Text is a free, in-browser tool for comparing two pieces of text and seeing what changed. Paste, drop in a file, or upload from disk. The diff runs locally and the result appears in the same page.
The site has a small set of rules it sticks to: no upload, no signup, no logging of what you paste. Ads pay for the hosting, but they stay out of the way and never see your text. The tool you see is the whole product. There is no premium tier hiding the useful features behind a paywall.
Why we built it
We kept running into the same need: compare two texts quickly online, without a signup, without a cluttered page, without wondering what the site does with what you paste. The tools available were limited. Most were slow, cluttered, or unclear about privacy.
So we built one for ourselves. It loads fast, runs in the browser, and gets out of the way. That is still the goal.
What we use it for ourselves
This tool is not theoretical. We use it every week. A short list of recent uses: reviewing translation revisions for the site itself, comparing two AWS IAM policies before applying the new one, spotting drift in Terraform plan output between two runs, and diffing two versions of a contract clause.
The variety matters. The same diff engine handles a 50-word paragraph and a 5,000-line config file, and the editor stays responsive in both. That is the bar.
What's not here
No analytics on your input — the text you paste is never uploaded or recorded. We use Google Analytics and Microsoft Clarity to understand how the site itself is used (page views, clicks, usage patterns), but neither is part of the diff engine. Ads come from Google AdSense and pay for the hosting; they cannot see what you paste. No pricing page. Sign in is optional and only needed if you want to save diffs to your account.
The details are on the privacy page, which also walks through how to verify the in-browser claim using your browser's DevTools Network tab, in about three minutes.
What's on the site
The current set of tools, all sharing the same diff engine and editor:
Compare Text is the original general-purpose text-diff tool, and the home page. Compare JSON adds JSON-aware formatting, minifying, and validation before the diff. Compare XML and Compare YAML do the same for those two formats. Contract Redline is the same engine framed for legal redlining, where the change list and the inline highlight matter more than the raw character count. The privacy page covers the data side.