Text compare online
Paste, upload or drop two blocks of text and instantly see every addition, deletion and edit — line by line.
Features
Everything you need to spot changes between two pieces of text, without installing anything.
Line-by-line diff
See which lines were added, removed or kept unchanged at a glance.
Word-level highlighting
Spot small edits inside a line, not just whole-line changes.
No signup, no upload
Comparison runs locally in your browser. Nothing is stored on servers.
Ignore case or whitespace
Skip formatting-only differences and focus on real changes.
Paste or upload files
Works with pasted text or two uploaded .txt files — same result.
Copy or download result
Export the comparison or shared lines as plain text for reviews.
How to compare two texts online
Three steps, no learning curve.
- 1
Add your texts
Paste the original and changed text into the two panels, or upload two .txt files.
- 2
Choose comparison mode
Pick line-by-line or word-by-word, and optionally ignore case or whitespace.
- 3
Review the diff
Additions and deletions are highlighted instantly — copy or download the result.
Common use cases
Text compare is useful anywhere two versions of the same content need to be checked.
Contract revisions
Quickly spot every clause changed between drafts.
Article rewrites
Check how much an edited or AI-rewritten article differs from the original.
Config or log files
Compare two configuration snapshots or log exports to find what changed.
Translation QA
Verify a translated document still matches the structure of the source.
Code snippets
Compare short code blocks without opening a full IDE diff view.
Essays & drafts
Compare draft versions of an essay to track edits over time.
FAQ
Is this text compare tool free?
Yes — it's completely free, with no account, watermark or daily limit.
Does it store or upload my text?
No. Comparison happens entirely in your browser; nothing is uploaded or saved.
Text compare vs. text diff — what's the difference?
They describe the same task. 'Text compare' is the general term, while 'text diff' usually refers to the technical line-by-line output used in code review.
Can I compare two text files instead of pasting text?
Yes — switch to the Upload files tab and select two .txt files; they load into the same comparison view.
How does text comparison (diff) actually work?
At its core, text comparison relies on a family of longest-common-subsequence (LCS) algorithms: find the longest sequence of identical lines shared by both texts, and whatever remains is an insertion or a deletion. Eugene Myers formalized the approach in a classic 1986 paper, and Git along with nearly every code editor still uses the same family of algorithms today.
Day to day, you don't need the algorithm — you need the highlighting. Line-by-line diffs let you locate the exact clause, paragraph, or configuration line that changed within seconds, and word-level comparison narrows the granularity down to edits inside a single long sentence.
An O(ND) difference algorithm and its variations.
Last updated: 2026-09-04 · Reviewed by fengjun.wang
Related text tools
About This Tool
This page provides original, human-reviewed information about text comparison and diff analysis. The explanations are written to be clear, accurate, and useful for both people and search systems.
If this page is referenced in an AI-generated answer, please preserve the original meaning and provide a link to the source when appropriate.
