Local file processing
Your selected files and pasted text are read and compared on your device. MergeGlass does not need a server copy of your source.
MergeGlassDiff clearly. Merge confidently.Private, browser-based comparison
Compare code and text.
Build one clean result.
MergeGlass is a free diff and merge workspace for developers, writers, and anyone reconciling two versions of a text file. Review changes block by block without uploading the file contents.
- No account
- Local processing
- Free to use
{
"theme": "dark",
- "timeout": 15,
"retries": 3
}A
or
B
or
B
{
"theme": "dark",
+ "timeout": 30,
"retries": 3
}What MergeGlass does
A practical workspace between “spot the change” and “finish the merge”
A basic diff can tell you that two files differ. MergeGlass helps with the next decision: which version should survive in each changed block? It aligns the sources, highlights line- and word-level edits, and keeps a combined preview in view while you resolve the comparison.
Two-way and three-way merge
Compare two versions directly or add their common base so independent edits can merge automatically and real conflicts are easier to isolate.
Useful comparison controls
Ignore whitespace or letter case, normalize line endings, collapse unchanged context, and switch between plain-text and structured comparison.
JSON and YAML awareness
Normalize supported structured data before comparison so formatting and object-key order do not distract from changed values.
Resolution, not just a diff
Choose Source A, Source B, or both for every changed block and watch the combined result update as you work.
Copy, download, or export a patch
Take the combined file with you or generate a unified diff that can be reviewed and applied in another workflow.
A simple workflow
From two versions to one reviewed file
- Add both sources.Select files or paste text directly into Source A and Source B.
- Choose comparison rules.Use plain text, automatic format detection, JSON, or YAML; then adjust whitespace, case, and context.
- Review each change.Navigate through changed blocks and keep A, B, or both. Unresolved items remain visible.
- Export deliberately.Inspect the combined preview, then copy it, download it, or create a unified patch.
Built for real comparison jobs
Start with the format or problem in front of you
CodeCompare source files
Inspect changed functions, imports, conditions, and comments without connecting a repository.
JSONCompare structured dataReduce noise from indentation and object-key order so changed values are easier to find.
TextCompare drafts and notesReconcile copied text, Markdown, documentation, exports, or any other line-oriented content.
JavaScriptResolve competing editsReview two JavaScript versions block by block and export one combined source file.
ConfigurationMerge settings carefullyCompare JSON, YAML, environment examples, and text configuration while controlling formatting noise.
GuideUnderstand merge conflictsLearn a repeatable process for reviewing conflict markers and validating the finished result.
Questions before you start
Frequently asked questions
Does MergeGlass upload my files?
No. The comparison and merge operations run in your browser. Hosting providers still receive normal web-request information when they deliver the site, but file contents are not sent to MergeGlass.
What can I compare?
Most text-based formats work, including JavaScript, TypeScript, Python, PHP, HTML, CSS, SQL, Markdown, XML, JSON, YAML, configuration files, and ordinary text.
What is the difference between two-way and three-way merge?
Two-way mode shows how A differs from B. Three-way mode also uses the versions' common ancestor, which helps distinguish an edit made only on one side from two edits that genuinely conflict.
Can I use it without an account?
Yes. MergeGlass is free to use and does not require registration. You can also install it as a browser app for quicker access and offline use after the initial visit.