Category: Application

application/wasm

application/wasm is the required MIME type for streaming WebAssembly binaries. WebAssembly.instantiateStreaming() strictly rejects any response that does not send application/wasm.

MIME / CONTENT-TYPE

application/wasm

ASSOCIATED EXTENSIONS

.wasm

PRIMARY CATEGORY

Application

HTTP Headers & Web Server Configurations

Standard HTTP Response Header

Content-Type: application/wasm

Send this exact header in HTTP responses to instruct browsers how to decode and render the payload.

Node.js / Express / Web API

const { instance } = await WebAssembly.instantiateStreaming(fetch("/module.wasm"));

NGINX Configuration (mime.types)

types {
    application/wasm wasm;
}

Apache (.htaccess / httpd.conf)

AddType application/wasm .wasm

Security Advisory & Hardening

Browsers require the exact "application/wasm" Content-Type header to compile WebAssembly in background threads without blocking the main UI thread.

Frequently Asked Questions

application/wasm Questions & Answers

Common questions regarding MIME types, Content-Type headers, and web server configurations.

The standard HTTP response header is: "Content-Type: application/wasm".

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