Merge YAML
Merge two YAML files online. Review each differing key, pick the value to keep, and export clean regenerated YAML. Free and private, with no upload.
Files never leave your browser.
About YAML Merge
Resolves differences between two YAML files at the key level, letting you pick which side wins per branch. Output is regenerated YAML. Comments are not preserved.
How to use
- Load both YAML files into the editors.
- For each differing key, pick Left or Right.
- Copy or download the merged YAML.
Try a sample
A database+cache config with a pool-size change and a new queue section.
What this tool doesn't handle
- Original comments and ordering are lost; the result is regenerated from the merged data structure.
- YAML-specific features (anchors, merge keys) are flattened before comparison.
Frequently asked questions
Do my files ever leave my browser?
No. Every comparison runs locally in your browser. Nothing you paste, drop, or load is uploaded to a server; the tool keeps working even if you go offline after the page loads.
Is this tool free to use?
Yes. All DiffResolver tools are free, with no account, sign-up, or installation. Because processing happens on your device, there are no server-imposed usage limits.
Are comments preserved in the merged YAML?
No. The output is regenerated from the merged data structure, so comments and original key order are lost. Re-add important comments after exporting.
Which side's formatting does the merged file use?
Neither; the output is consistently re-serialized YAML. Values come from whichever side you picked per key; formatting is uniform regardless of source.
Is there a file size limit?
No server limit applies, because nothing is uploaded. The memory of your device sets the practical limit. Above 10 MB for text, 40 MB for images, 100 MB for documents, or 500 MB for archives, the tool warns you that the work can be slow, but it never blocks the file.
Does this tool work offline?
Yes. The browser keeps a copy of the tool after the first visit, so a page you opened before still works without a network. You can also install DiffResolver as an app from the browser menu. Installation stays optional; the site works the same in a normal tab.
Where is my data stored?
Your files are stored nowhere. They stay in the memory of the page and are gone when you close the tab. Only what you save yourself stays in this browser: a snapshot, your tool options, and your theme. To remove it, open Settings and select Clear all local data.