Anvil Tools
Word & Character Counter
Count words, characters, sentences, and estimated reading time as you type.
Open tool →Text Difference Checker
Compare two versions of text with a deterministic line-by-line diff that marks unchanged, removed, and added lines.
Line-based comparison. The two line counts multiplied together must not exceed 2,000,000.
Compare two texts
Read a replacement as two changes
Compare the sample texts to see one removed line, one added line, and two unchanged lines. A moved line can also appear as a removal and addition. The workload limit is the product of the two line counts: at most 2,000,000.
| Input or check | Expected result or decision |
|---|---|
| Before: alpha / beta / gamma | After: alpha / delta / gamma. |
| beta → delta | One removed line and one added line; this is not a character-level edit. |
| An extra space on a line | A text change; formatting and document layout are not compared. |
| Before: alpha / beta / gamma; after: gamma / alpha / beta | gamma appears removed and added; alpha and beta remain unchanged. This comparison does not label a move. |
How it works
- Paste the earlier text on the left and the changed text on the right.
- The tool uses a longest-common-subsequence comparison at line level.
- Green rows are additions, red rows are removals, and neutral rows are unchanged.
Common uses
- Reviewing edits to configuration or copy.
- Finding changed lines between two lists.
- Checking a generated file against an earlier version.
Your input stays in this browser. Nothing entered into this tool is sent to the Anvil Tools server.
A practical walkthrough
- Place the original text on the left and an edited version on the right, then compare the two versions.
- Read added and removed lines together. Moving a line may appear as a removal and addition rather than a separate move.
- Read the added and removed lines and their line numbers. This tool displays a comparison and has no export button.
Tips for a reliable result
The comparison works line by line. Very large inputs can exceed the comparison limit; compare smaller sections when that happens.
What to use next
These tools open separately; inputs are not transferred.
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Open tool →How this tool handles your data
Both text versions are compared in your browser and are not sent to an Anvil processing server.
Known limitations
The comparison is line-oriented, not semantic. Reordered blocks, equivalent formatting, word-level changes, and very large documents may require a specialized diff tool.
Related guide and Lab test
Questions and troubleshooting
Does it compare individual characters?
No. It compares complete lines, which keeps code, lists, and configuration changes readable.
Why is there a size limit?
Exact line comparison uses memory proportional to both line counts. The limit prevents a very large paste from freezing the browser.
When a comparison is too large or unexpected
Compare a smaller section if the workload limit is reached. Check blank lines and whitespace in both sources. This tool compares text lines, so moved lines can appear as removals and additions; it does not inspect rich-document formatting.
Does it compare document formatting?
It compares pasted plain text by line. Fonts, page layout, tracked changes, and rich-text formatting are not part of the comparison.
Why does a moved line appear twice?
A line-based comparison can represent a move as a removed line and an added line. Read those changes together before accepting a revision.
Explore practical guides and experiments
How to Review Text Changes Before Publishing: A Practical Guide to Line-by-Line Diffs
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