text/html.html.htmtext/css.csstext/javascript.js.mjstext/plain.txttext/csv.csvtext/xml.xmltext/markdown.md.markdowntext/calendar.icstext/tab-separated-values.tsvtext/vcard.vcf.vcardimage/jpeg.jpg.jpegimage/png.pngimage/gif.gifimage/webp.webpimage/svg+xml.svg.svgzimage/avif.avifimage/bmp.bmpimage/tiff.tif.tiffimage/ico.icoimage/x-icon.icoimage/heic.heicimage/apng.apngaudio/mpeg.mp3audio/ogg.oga.oggaudio/wav.wavaudio/webm.webaaudio/flac.flacaudio/aac.aacaudio/midi.mid.midiaudio/opus.opusaudio/mp4.m4avideo/mp4.mp4.m4vvideo/webm.webmvideo/ogg.ogvvideo/mpeg.mpeg.mpgvideo/quicktime.mov.qtvideo/x-msvideo.avivideo/3gpp.3gpvideo/x-matroska.mkvvideo/x-ms-wmv.wmvapplication/json.jsonapplication/ld+json.jsonldapplication/xml.xmlapplication/pdf.pdfapplication/zip.zipapplication/gzip.gzapplication/x-tar.tarapplication/x-7z-compressed.7zapplication/x-rar-compressed.rarapplication/javascript.jsapplication/ecmascript.esapplication/typescript.tsapplication/wasm.wasmapplication/octet-stream.*application/x-www-form-urlencoded-multipart/form-data-application/graphql.graphqlapplication/sql.sqlapplication/x-sh.shapplication/x-python-code.pycapplication/msword.docapplication/vnd.openxmlformats-officedocument.wordprocessingml.document.docxapplication/vnd.ms-excel.xlsapplication/vnd.openxmlformats-officedocument.spreadsheetml.sheet.xlsxapplication/vnd.ms-powerpoint.pptapplication/vnd.openxmlformats-officedocument.presentationml.presentation.pptxapplication/vnd.oasis.opendocument.text.odtapplication/vnd.oasis.opendocument.spreadsheet.odsapplication/vnd.oasis.opendocument.presentation.odpfont/ttf.ttffont/otf.otffont/woff.wofffont/woff2.woff2font/collection.ttcmultipart/mixed-multipart/alternative-multipart/related-message/rfc822.eml.mhtmessage/partial-application/json.jsonREST API responses, config files
text/html.htmlWeb pages served by browsers
text/css.cssStylesheets for web pages
text/javascript.jsJavaScript files (IANA official)
multipart/form-dataFile uploads in HTML forms
application/pdf.pdfDocument downloads & previews
image/webp.webpModern web images (best compression)
application/octet-stream.*Generic binary / force download
application/wasm.wasmWebAssembly modules
MIME 類型出現在 HTTP 響應的 Content-Type 標頭中，使瀏覽器和客戶端了解如何處理內容。
HTTP/1.1 200 OK
Content-Type: application/json; charset=utf-8
Content-Length: 1024
{"status": "ok"}
# File upload request:
Content-Type: multipart/form-data; boundary=----FormBoundary123
# Force browser download:
Content-Type: application/octet-stream
Content-Disposition: attachment; filename="report.xlsx"Content-Type: application/jsonMIME（多用途互聯網郵件擴展）類型是用於指示文檔、文件或字節集合的性質和格式的標準標識符。由類型和子類型組成，例如 'text/html' 或 'application/json'。服務器和瀏覽器使用 MIME 類型來確定如何處理文件。
將 Content-Type HTTP 標頭設置為適當的 MIME 類型。例如：Content-Type: application/json; charset=utf-8。Apache 和 Nginx 等 Web 服務器可以自動將文件擴展名映射到 MIME 類型。在 Express.js 中，使用 res.type('json') 或 res.setHeader('Content-Type', 'application/json')。
application/json 是 JSON 數據的官方 IANA 注冊 MIME 類型，應始終使用。text/json 是非標準的，歷史上曾使用過。現代 API、框架和瀏覽器都期望 JSON 有效負載使用 application/json。
使用 application/octet-stream 作為通用二進制下載類型，強制瀏覽器下載而不是顯示文件。對於特定格式，使用適當的類型（例如 PDF 使用 application/pdf）。結合 Content-Disposition: attachment; filename='file.ext' 顯示下載提示。