HTTP Header Diff & Compare
Paste two HTTP header sets to see highlighted line-by-line differences, a change summary, and a similarity percentage. Everything is processed on your device.
Everything runs in your browser. Your data is never sent to our servers.
Example
Example Input
two response header sets
Example Output
differing headers highlighted
How to Use
- 1Paste the first HTTP header sets (A) in the left box and the second (B) in the right box.
- 2Adjust the options if needed (ignore case, whitespace, or empty lines).
- 3Click Compare (or press Ctrl+Enter).
- 4See the highlighted differences, a summary of how many changes there are, and the similarity percentage. Switch between side-by-side / unified / inline views.
About HTTP Header Diff & Compare
HTTP Header Diff & Compare parses two sets of HTTP headers (one per line, "Name: Value") then compares them header by header. Header names are case-insensitive, so the comparison follows the standard.
Useful for debugging differences between responses from two servers, environments, or cache/CORS configurations.
FAQ
What is the difference between "diff" and "compare"?
Both are done by the same tool. "Diff" highlights the lines/parts that changed (added/removed), while "compare" shows how similar the two inputs are (similarity percentage + summary). You get both at once here.
Is my data sent to a server?
No. The entire comparison is computed in your browser with JavaScript. Nothing is uploaded, logged, or stored on our servers — safe for sensitive data.