Know what the browser can do.

Supported browsers

Feature requirements

• WebAssembly is required for every codec. If Wasm is disabled, no tool can run.
• OffscreenCanvas is used to resize images before encoding. Supported target browsers provide it.
• WebCodecs is used for video. When a codec cannot be configured, Morsel prefers a remux path and states the fallback in the interface.
• File size and memory limits are checked before a job starts. They are shown on the tool page and on the pricing comparison.

HEIC depends on Wasm

HEIC decoding uses libheif-js in WebAssembly. It is heavier than JPEG or PNG decoding and needs more memory for large images.

Every HEIC input is converted to JPEG, PNG, or WebP; this build cannot encode HEIC. A 48 MP HEIC can exhaust memory on a phone, so large images should be processed on a desktop when possible.

Mobile limits

Mobile browsers can run the same checks, but memory and background-tab limits are tighter. A job that exceeds a limit is blocked before credits are reserved. All six tools are connected; video additionally needs WebCodecs support in the browser.

Not supported

• Internet Explorer and other browsers without WebAssembly.
• Browsers with WebAssembly or JavaScript disabled.
• Private windows that block sessionStorage: the job still runs, but a retry after a lost response may reserve twice because the idempotency key cannot persist.