navigator.mimeTypes is a read-only Navigator property that returns a MimeTypeArray (MDN). Modern engines hard-code the list: either application/pdf and text/pdf (inline PDF supported) or an empty list.
Read the notes below before you rely on this property. Prefer feature detection when support is limited.
Use navigator.mimeTypes. Start with this line.
navigator.mimeTypes| Call | What it does |
|---|---|
navigator.mimeTypes | Primary signature. |
Built into the browser. Read navigator.mimeTypes on Navigator — no import required.
navigator.mimeTypesThis member has no parameters beyond those shown in the signature.
| Return Value | Description |
|---|---|
| * | The current value of navigator.mimeTypes. |
lengthSee how many MIME types this browser reports.
const types = navigator.mimeTypes;
console.log("length: " + types.length);
console.log("type: " + typeof types);MimeTypeArray, not a plain array.length. Modern browsers: 0 or 2.application/pdf (MDN)Use the in operator to see if the PDF MIME type is listed.
if ("application/pdf" in navigator.mimeTypes) {
console.log("PDF MIME type listed (inline PDF likely)");
} else {
console.log("application/pdf not in mimeTypes");
}in. MDN’s recommended named-property check.text/pdf matches. Current browsers expose both or neither.pdfViewerEnabled for products. Safer Boolean for UI.description + suffixesRead the hard-coded PDF plugin description and file suffixes (MDN).
if ("application/pdf" in navigator.mimeTypes) {
const { description, suffixes } =
navigator.mimeTypes["application/pdf"];
console.log("Description: " + description + ", Suffix: " + suffixes);
} else {
console.log("No PDF MimeType entry");
}in. Avoid reading a missing named entry.description and suffixes are strings.pdfViewerEnabledCompare the legacy MIME check with the modern Boolean API.
const hasPdfMime = "application/pdf" in navigator.mimeTypes;
const pdfEnabled = Boolean(navigator.pdfViewerEnabled);
console.log("application/pdf in mimeTypes: " + hasPdfMime);
console.log("pdfViewerEnabled: " + pdfEnabled);
console.log("Prefer pdfViewerEnabled for new PDF UI decisions");pdfViewerEnabled is the dedicated Boolean.mimeTypes.item()Walk the array-like list by index (length may be 0 or 2 today).
const types = navigator.mimeTypes;
const lines = ["length: " + types.length];
for (let i = 0; i < types.length; i++) {
const mt = types.item(i);
lines.push((i + 1) + ") " + mt.type);
}
console.log(lines.join("\n"));item(i). Classic MimeTypeArray accessor (or types[i]).type. The MIME string for that entry.for…in. Named properties are not enumerable on modern browsers.navigator.mimeTypes is Baseline Widely available (MDN, since about July 2015). The MimeTypeArray interface is Deprecated; modern engines return a hard-coded PDF list or empty.
Supported widely for years. Treat contents as hard-coded PDF metadata (or empty), and prefer pdfViewerEnabled for new checks.
Bottom line: Safe to read for learning and legacy code. For product PDF decisions, use navigator.pdfViewerEnabled.
Learn how navigator.onLine reports a simple online/offline Boolean.
10 people found this page helpful