Free, browser-based utilities for everyday developer workflows

Diff two text files

Paste two versions of a file — config, release notes, output — and see a line-by-line diff of what changed. No upload, no install.

Open this example in Text Diff

Open the tool, then paste the sample input below. Everything runs locally in your browser.

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The problem

Two versions of a config or a log look almost identical and you need to find the one line that differs. Scanning by eye is error-prone. A line-by-line diff highlights exactly what was added, removed, or changed.

Sample input

Version A
host=localhost
port=8080
debug=false
Version B
host=localhost
port=9090
debug=true

Expected output

Diff
  host=localhost
- port=8080
+ port=9090
- debug=false
+ debug=true

Unchanged lines are shown for context; removed lines are marked - and added lines +.

How to do it

  1. Paste the first version on the left.
  2. Paste the second version on the right.
  3. Run the diff.
  4. Read the added and removed lines.
  5. Copy the changed lines you need.

Common mistakes

  • Trailing whitespace that makes identical lines look different.
  • Mixed line endings (CRLF vs LF) flagged as changes.
  • Comparing reordered lines where order is not meaningful.
  • Pasting only part of one file so everything after looks added.
  • Expecting a word-level diff when the tool compares lines.

Related tools

Related guides

FAQ

How do I compare two text files?

Paste each version into one side and run the diff. The tool aligns the lines and marks what was added, removed, or unchanged.

Why are identical-looking lines marked as different?

Usually trailing whitespace or different line endings. Normalize whitespace and line endings so only real changes remain.

Does it diff line by line or word by word?

It compares line by line, marking whole lines as added or removed. That is ideal for config files and logs.

Can I compare config files?

Yes. A line diff is well suited to config and environment files, where each setting is on its own line.

Is my text uploaded?

No. The comparison runs locally in your browser. Neither file is sent to a server.

Text diffing runs locally in your browser. Your files are not uploaded.

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