What is Text Diff Checker?
Text Diff compares configuration, logs, code snippets, and copy revisions at line level. The page keeps original and revised text separate, normalizes common line endings, and uses a longest-common-subsequence calculation to mark inserted, deleted, and unchanged lines. It never merges automatically or overwrites either source. Common workflows include the following. Compare configuration or environment lists before and after a deployment. Review changes between two announcements, translations, or API examples. Locate added, removed, and stable records in log snapshots. The page also documents input boundaries, output behavior, and practical cautions so you can review the result before putting it into an application, configuration, test, or production workflow.
When to use it
- Compare configuration or environment lists before and after a deployment.
- Review changes between two announcements, translations, or API examples.
- Locate added, removed, and stable records in log snapshots.
How to use it
- Enter the original text on the left and revised text on the right.
- Run a line comparison.
- Review plus, minus, and unchanged lines and copy the diff.
- Load one of the realistic examples first to verify the selected options and processing direction before replacing it with your own data.
- Review the output, status message, and documented limits; copy, download, or continue only after the result matches your expectation.
Runnable examples
The “Example 1” and “Example 2” buttons load the matching inputs. They cover different structures, directions, or boundaries and can be run directly in the workspace.
Example 1
name=JSONLane
tools=20
theme=lightExample 2
version=1.5
status=review
branch=mainInput rules
- The left side is the original version and the right side is the revised version.
- CRLF, CR, and LF are normalized to LF before line comparison.
- Each side is limited to 2,000 lines to bound calculation time and memory.
- Text input is counted before processing and is limited to 200,000 characters on this page; file modes apply the separate file limit shown in the workspace.
- Each side is limited to 2,000 lines.
Output rules
- Removed lines use a minus marker, additions use a plus marker, and unchanged lines keep a space prefix.
- A moved line normally appears as a deletion followed by an addition.
- The result describes text changes only and does not understand code or configuration semantics.
- Output reflects only the current input, direction, and options; rerun after changing a mode or value instead of treating an earlier result as current.
- Moved lines usually appear as remove plus add.
Limitations and cautions
- Each side is limited to 2,000 lines.
- Moved lines usually appear as remove plus add.
- The comparison does not understand code syntax or semantics.
How your data is handled
Both texts and the diff matrix stay in browser memory. No content is uploaded, versioned, or sent to an external comparison service.