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About this tool
Look up the MIME type for a file extension, or every extension for a MIME type, with charset and compression guidance.
This tool maps a file extension to its correct MIME type — the Content-Type value a server should send — and, in reverse, lists every conventional extension for a given MIME type. Mappings follow the IANA Media Types registry with charset guidance from RFC 6838, so developers configuring servers, upload validators or CDNs get the exact header value plus a note on whether gzip or Brotli compression is worth applying.
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Search extension to MIME type or MIME type to extensions in one tool.
Each type says whether to append charset=utf-8, per RFC 6838 and the format's own spec.
Shows whether wire compression helps or the format is already compressed, like JPEG, ZIP and WOFF2.
Use text/javascript. RFC 9239 (2022) made text/javascript the sole standard MIME type for JavaScript and marked application/javascript obsolete, although browsers still accept the older value. ES modules (.mjs) use the same text/javascript type.
No. RFC 8259 requires JSON exchanged between systems to be encoded in UTF-8, so a charset parameter on application/json has no effect. Sending plain application/json is correct; adding ; charset=utf-8 is harmless but redundant.
application/octet-stream. It tells the browser the body is arbitrary binary data, so the file is downloaded rather than rendered or sniffed. Pair it with X-Content-Type-Options: nosniff to stop browsers second-guessing the type.
Usually not. WOFF2 fonts are Brotli-compressed internally, WOFF uses zlib, and JPEG, PNG, WebP, AVIF, ZIP and PDF are already compressed, so re-compressing wastes CPU for near-zero savings. Text formats — HTML, CSS, JavaScript, JSON, SVG — and uncompressed binaries like TTF or TAR do benefit from gzip or Brotli.