Text Diff
Compare two text documents line by line.
This runs in your browser. Nothing is uploaded.
Drop a file here or choose oneChoose file
Drop a file here or choose oneChoose file
Compare two documents line by line
Text Diff places two text documents side by side and reports the lines that changed. Paste source code, configuration, logs, release notes, or any other plain text into the left and right editors. The page compares the text locally and keeps the original inputs unchanged.
Use the sample to see a changed line and an added line, then use Copy summary for a compact record of the result. Line labels such as L2 point back to the relevant position in the comparison. For structured JSON,JSON Diff parses values before it compares them and ignores object key order.
Added, removed, and changed lines
An added item exists on the right but not the left. A removed item exists on the left but not the right. A changed item has content on both sides that differs. The badges use separate tones so the change type remains visible at a glance, while the line label and text provide the useful detail.
An empty right editor is valid. If the left side contains text, those lines are reported as removed. If both editors contain the same text, the page shows No differences. The tool does not merge, patch, or write either source automatically.
Whitespace is part of text
By default, plain text comparisons treat spaces, tabs, and capitalization as input. A line that looks the same in a proportional font can still differ because it has extra whitespace or different letter case. CRLF and LF line endings are normalized before comparing. Use the comparison options when whitespace or capitalization should not count as a change.
For a repeatable review, paste both versions from the same source type and keep generated files in their original encoding. If the result is unexpectedly large, first check whitespace, capitalization, and formatting changes before searching for a semantic change.
Private review in the browser
The two texts never leave this browser. Nothing is uploaded, and the copy summary contains only the differences you choose to copy. Review the summary before sharing it because it can include secrets from the source. For a JSON-specific workflow, seeJSON Diff; for pattern checks, useRegex Tester.
FAQ
Does Text Diff upload either document?
No. Both texts are compared in your browser. After the page loads, it still works in airplane mode. TheDevTab never receives either document.
How does the comparison work?
The tool compares the two inputs line by line and reports changes with a line label such as L3. It does not rewrite either source.
What do added, removed, and changed mean?
Added means text exists on the right, removed means it exists only on the left, and changed means the line content differs between the two inputs.
What happens when the right side is empty?
Lines present on the left are shown as removed items. An empty right side is a valid comparison, not an invalid document.
What does No differences mean?
It means the comparison found no line changes. Whitespace still matters by default, while CRLF and LF line endings are normalized before comparing.
Can I copy a diff summary?
Yes. After a comparison with changes, Copy summary writes the change type, line label, and line text to your clipboard as plain text.