How to use this checker
Load both versions
Paste your text or upload a local file into the Original (A) and Changed (B) inputs.
Tune the comparison
Choose between split or unified view. Toggle word-level diff, ignore whitespace, or ignore case to filter out noise.
Read the result
Review the highlighted additions, removals, and modifications side-by-side. Use keyboard shortcuts or the changes only toggle to navigate large files.
Export the patch
Copy or download the unified diff as a .patch file for sharing or applying with Git.
Compare Text Locally in Your Browser
Tool127 Text Diff Checker compares two versions of text directly on your device. You can paste content, type manually, or load local text files without uploading compared content to a server.
This is useful for reviewing code snippets, logs, configuration files, JSON payloads, CSV exports, documentation drafts, support tickets, and AI-generated rewrites.
Text Diff vs Code Diff vs File Diff
A text diff compares two pieces of plain text and highlights what was added, removed, or modified.
A code diff uses the same idea for source code, configuration files, JSON payloads, scripts, and generated code.
A file diff compares the content of two local text-based files. In Tool127, supported files are read in your browser and compared locally.
Side-by-Side Diff vs Unified Diff
Side-by-side diff is best when you want to compare both versions with context. It keeps the original and changed text in separate columns, making line-by-line review easier.
Unified diff is more compact and closer to Git patch format. It is useful when you want to copy changes into a code review, ticket, pull request, or patch file.
Common Diff Options Explained
Ignore whitespace
Useful when formatting changed but the real content stayed the same.
Ignore case
Useful when uppercase and lowercase differences are not important.
Word-level diff
Best for paragraphs, documentation, AI rewrites, and readable text.
Character-level diff
Best for short strings, IDs, encoded values, or small syntax changes.
Changes only
Useful for large files because it hides unchanged lines and lets you focus only on the differences.
When to Use a Text Diff Checker
Use a text diff checker when you need to:
- Compare two versions of a code snippet before creating a pull request
- Review changes between generated AI text and the original text
- Compare logs from two environments
- Compare JSON or CSV exports
- Check configuration changes
- Find invisible whitespace changes
- Review documentation changes
- Generate a unified patch for sharing
Frequently Asked Questions
What is a text diff checker?
A text diff checker compares two pieces of text and highlights what was added, removed, or modified.
Is my text uploaded to a server?
No. Supported comparison workflows run locally in your browser. Tool127 does not upload compared text or file content for normal diff processing.
Can I compare code snippets?
Yes. You can compare JavaScript, TypeScript, JSON, CSS, HTML, logs, configs, and other UTF-8 text-based content.
Can I compare two files?
Yes. You can load two supported local text files and compare their content in your browser.
What is the difference between split and unified diff?
Split view shows original and changed text side by side. Unified view shows additions and removals in one compact stream.
Can I ignore whitespace?
Yes. Use the Ignore whitespace option to reduce noise from formatting-only changes.
Can I download a patch file?
Yes. The tool supports copying or downloading a unified-format .patch file.
Can I compare JSON files?
Yes. You can compare JSON as text. For best results, format both JSON documents first with the JSON Formatter, then compare the formatted output.
Related Text and Developer Tools
Continue with nearby local-first tools for formatting, decoding, generating, and comparing developer data.
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