HTTP • Byte ranges • 206 / 416
Range Header Builder & Partial Content Tester
Build precise Range requests, preview matching Content-Range responses, validate resumable download behavior, and see when your request would return 206 Partial Content or 416 Range Not Satisfiable.
Build headersCreate single, suffix, open-ended, and multipart byte ranges.
Simulate server logicPreview response status, served length, and exact offsets.
Plan resumesSee how to continue large downloads safely after interruption.
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Request builder
Enter the full resource size, then define one or more byte ranges. The tool will normalize them, generate the request header, and predict the server response.
Used to validate ranges and calculate
Content-Range.
HTTP range requests are usually byte-based.
Multipart only makes sense for multiple valid ranges.
One range per line. Supported formats:
start-end, start-, or suffix -length.
Quick outputs
206Expected status
2,560 bytesServed bytes
3 rangesParsed entries
multipart/byterangesLikely body type
Header preview
Range request
Server response
cURL example
Range breakdown
| # | Requested | Resolved | Length | Result |
|---|
Download resume planner
Use this when a download stopped mid-transfer and you know how many bytes already landed.
Implementation notes
206 Partial Content
Returned when at least one requested range is satisfiable and the server supports range requests.
Returned when at least one requested range is satisfiable and the server supports range requests.
416 Range Not Satisfiable
Returned when every requested range falls completely outside the resource. Servers should include
Returned when every requested range falls completely outside the resource. Servers should include
Content-Range: bytes */SIZE.
Heads-up
Some servers ignore complex multipart ranges, coalesce overlapping ranges, or strip support entirely. Always verify with real infrastructure when CDN or proxy layers are involved.
Some servers ignore complex multipart ranges, coalesce overlapping ranges, or strip support entirely. Always verify with real infrastructure when CDN or proxy layers are involved.