Why does resuming a download give 416?
The file on the server is shorter than the point you are resuming from, usually because it changed. Restart the download from zero.
HTTP 416 RANGE NOT SATISFIABLE
The requested byte range is outside the resource. 416 belongs to the 4xx client error class and is defined in RFC 9110.
Loading the workbench.
About HTTP 416
What Does HTTP 416 Range Not Satisfiable Mean?
The requested byte range is outside the resource. The code is registered with IANA and defined in RFC 9110.
Client error: the request has a problem, so it cannot be fulfilled as sent. Every code from 400 to 499 shares that general meaning, so a client that does not recognise 416 must treat it like 400.
When Do You See a 416 Response?
416 Range Not Satisfiable means none of the byte ranges in the Range header overlap the resource. It typically happens when a download manager tries to resume a file that has since shrunk or been replaced, when a client asks for bytes beyond the end of the file, or when the range syntax is invalid. Video players can trigger it after the file on the server changed mid-stream.
How Do You Fix a 416?
Servers should send Content-Range: bytes */ followed by the full length, so the client learns the actual size. Clients should restart the download from the beginning or request a valid range. Using If-Range with the original ETag avoids the problem, since a changed file is then returned in full with a 200 instead of failing.
What Does a 416 Response Look Like?
HTTP/1.1 416 Range Not Satisfiable
Content-Range: bytes */146515
Content-Length: 0416 is not cacheable by default: a browser or CDN stores it only when Cache-Control or Expires explicitly allows it.
To inspect a real one without sending it anywhere:
- Copy the response headers from your browser Network tab, or from
curl -i. - Paste them into the Header decoder to see every header explained.
- Check caching in the Cache lane.
Which Status Codes Are Related to 416?
- 206 Partial Content: Only the requested byte range is returned. Used for resumable downloads and video seeking.
- 200 OK: The request succeeded. The body depends on the method.
- 412 Precondition Failed: An If-Match or If-Unmodified-Since condition was false. Used for optimistic locking.
Browse every code on the HTTP status codes page.
What Other Lanes Are in the Reference Section?
- HTTP status codes: Every IANA-registered status code, with a page per code.
- MIME types: File extensions to Content-Type, searchable both ways, plus a Content-Type parser.
- HTTP methods: GET, POST, PUT, PATCH, DELETE and the rest: safe, idempotent, cacheable.
Elsewhere in 2http: Header decoder, Cookie decoder, Cache-Control decoder, CORS checker, User-agent parser, and all eleven lanes on the 2http home page. Part of the 2suite.io privacy-first ecosystem.
Frequently Asked Questions
What does Content-Range: bytes */1234 mean?
It is how a 416 tells the client the full size of the resource, 1234 bytes here, without sending any of it.
Is HTTP 416 an error?
Yes. 416 is a client error response: the problem is in the request, so repeating it unchanged will usually fail again.
Is a 416 response cacheable by default?
No. Caches store a 416 only when Cache-Control or Expires explicitly allows it.
How Can You Verify That Nothing Leaves This Browser?
You do not have to take our word that your headers stay here. Developer tools show every request a page makes, so you can watch this page work and confirm that nothing is sent. The check takes under a minute.
- Open your browser developer tools with
F12, orCmd+Option+Ion a Mac, and select the Network tab. - Reload the page and let it finish. You will see the page's own files, its web fonts, and one anonymous page-view request. Nothing has been typed yet, so none of them can contain your headers.
- Click the clear icon in the Network tab so that the log is empty.
- Paste real headers into any lane and read the result.
- Look at the Network tab again. It is still empty. For extra proof, turn on offline mode after the page loads and every lane keeps working.
Only two things can add a line to that log, and neither carries your headers. Submitting the feedback form sends the vote and comment you typed. Typing characters in a script the page has not displayed yet, such as Cyrillic or Greek, can make the browser fetch the matching font file, and that request names only the font.
2http never sends a request on your behalf: the request builder writes code for you to run, and the meta inspector reads source you paste instead of fetching a URL. The production site also sends a Content-Security-Policy header that tells your browser to refuse connections to anywhere except this site and the anonymous analytics endpoint.