Diff Checker

Compare two texts and see exactly what changed.

FREE - NO SIGN-UP - RUNS ON YOUR DEVICE

Runs in your browser tab

  • 2comparison levels
  • 2switches
  • 0uploads
  • 1 tapto copy
Specification

Diff Checker at a glance

Input
Two boxes of text
Levels
Line level or word level
Ignore whitespace
Spacing changes ignored
Ignore case
Capital changes ignored
Count
Added, removed, unchanged
Output
Highlighted, or plus and minus
Price
Free
Account needed
None
Where processing happens
On your device
How to

How to use Diff Checker

  1. 1

    Paste both versions

    Paste both versions.

  2. 2

    Choose the level

    Choose line or word.

  3. 3

    Read or copy

    Read or copy the result.

Questions

Frequently asked questions

What is the difference between line and word level?

Line level marks whole lines that changed, which suits code and configuration. Word level marks the words inside a line, which suits prose where one word moved.

When should I ignore whitespace?

When only indentation or spacing moved. Reindented code shows as a wholesale rewrite otherwise, and the switch clears that noise away in one tap.

Are my texts uploaded anywhere?

No. The comparison runs in this browser tab and neither text is sent to a server. Close the tab and nothing is left behind.

Can I compare two files?

Open each one, copy its contents and paste it into a box. This page compares text you paste rather than reading files from your disk.

Background

Reading the result

Paste the original on the left and the changed version on the right. Additions are shown in green and removals struck through in red, with a plain count of what moved.

  • Green means added to the second version; struck-through red means removed from the first.
  • The count is in lines or words, matching whichever level you chose.
  • Swap the two sides to see the same change described the other way round.
  • The copied version marks each line with a plus, a minus or a space.

Full specification

Specification of the Diff Checker tool
InputTwo boxes of text, both already filled with a sample so the marking explains itself.
LevelsLine level for whole lines that changed, word level for the words inside a line.
Ignore whitespaceLines that differ only in spacing or indentation are counted as unchanged.
Ignore caseText that differs only in capitals is counted as unchanged.
CountAdded, removed and unchanged, counted in lines or words to match the level chosen.
OutputHighlighted text on the page, and a plus and minus marked copy for pasting elsewhere.
PriceFree. Supported by clearly labelled ads outside the working area.
Account neededNo.
Where processing happensIn your browser tab. Nothing is uploaded.
Next step

Keep going with the same files

All developer tools: Developer tools on SPOTTOOLS