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ConvenTools

Diff Checker

Runs in your browser — your files never leave your device

Paste two versions of any text and instantly see what changed — added lines in green, removed lines in red, line by line. Great for comparing configs, drafts, code snippets or logs, all without anything leaving your browser.

Original
Changed

How to use it

  1. 1
    Paste the original

    Put the first version of your text into the “Original” box on the left.

  2. 2
    Paste the changed version

    Put the second version into the “Changed” box on the right. The diff updates as you type.

  3. 3
    Read the result

    Review the highlighted output: green lines were added, red lines were removed, and the counts show the totals. Toggle “ignore whitespace” to hide spacing-only changes.

See every change at a glance

A diff makes the difference between two texts obvious: instead of squinting to spot a changed word, you get a clear line-by-line view of exactly what was added and removed, with original and changed line numbers side by side.

The optional “ignore whitespace” mode hides differences that are only spacing or indentation, so you can focus on changes that actually matter.

Private by default

The comparison runs entirely in your browser with a well-tested diff algorithm — your text is never sent to a server. That makes it safe for comparing sensitive things like configuration files, contracts or private drafts.

Because there is no upload, it is also instant and works offline once the page has loaded.

Frequently asked questions

Is my text uploaded or stored anywhere?

No. The comparison runs entirely in your browser and your text is never sent to or stored on a server — it never leaves your device, so it is safe for sensitive content.

What kind of diff is this?

It is a line-level diff: each line is compared as a whole, and changed lines appear as a removal followed by an addition. This is the same model used by tools like git diff.

What does “ignore whitespace” do?

It treats lines that differ only in spacing or indentation as unchanged, so reformatting does not clutter the result with noise.

Is there a size limit?

There is no fixed limit — comparison happens on your own device, so very large texts are only bounded by your browser’s memory.