Online Text Diff Checker
Free online diff checker to compare two text strings, code revisions, or config files side-by-side with file upload & inline character highlights.
How to Use Online Text Diff Checker
Strinza Diff Checker provides line-by-line and character-level difference analysis for code, text documents, and configuration files.
1. Upload or Paste
Upload files or paste original and modified text strings into String A and String B.
2. Inline Word Highlights
Exact word additions and deletions are highlighted with colored background tokens.
3. 100% Client-Side
All diff calculations execute locally in your browser with zero server data uploads.
About the Diff Checker
The Diff Checker compares two blocks of text line by line and highlights exactly what was added, removed or changed. It is built for the everyday cases that do not justify a Git commit: reconciling two .env files, spotting the one differing field between an expected and actual API response, or checking which key went missing from a translation file. Added lines are highlighted in green, removed lines in red, and a summary reports the counts.
How to use the Diff Checker
- Paste the original text into the left panel.
- Paste the changed text into the right panel.
- Review the highlighted additions and deletions, and the change summary.
Frequently asked questions
Can I compare JSON or code files?
Yes. The comparison is line-based and format agnostic, so JSON, YAML, SQL, source code and plain prose all work. For JSON, run both sides through the Code Formatter first so that key ordering and indentation differences do not create noise.
Is there a size limit?
There is no hard limit, but because the diff runs in your browser, very large inputs of several megabytes may feel slow on low-powered devices. For typical config files, logs and API payloads it is instant.
Are my files uploaded anywhere?
No. The diff algorithm runs entirely client side. Nothing you paste leaves your machine, which makes it safe for proprietary code and configuration containing internal hostnames.
Related tools
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- Format ConverterConvert between JSON, XML, YAML and CSV online. Fast, accurate structural conversion that runs entirely in your browser with no uploads.
Diff Checker is free to use with no account, no ads and no usage limits. Every calculation runs locally in your browser, so nothing you paste is ever uploaded. See our privacy policy.