A 10 KB WEBP test file

About this file

A 10 KB test file in WEBP format, sized to exactly 10,240 bytes. Free to download with no signup, for verifying upload limits and file-handling behaviour.

The MD5, SHA-1 and SHA-256 values listed above are the real digests of this file. Recomputing them after download confirms the transfer was not corrupted, and they double as known-good expected values when testing a hashing library.

What this size means in practice

10 KB sits below virtually every upload limit, which makes it the baseline "happy path" case. Confirm this file goes through first, then move up in size to probe where your limits actually bite.

It also fits inside the AWS Lambda asynchronous invocation payload cap (256 KB) and typical API JSON body limits. The size is convenient for CI fixtures and unit-test data you commit to a repository.

Getting a feel for this size

On a 10 Mbps link the transfer takes roughly 8 ms, and about 1 ms at 100 Mbps. Base64-encoded it grows to roughly 13 KB.

Estimating a photographic WEBP at roughly 0.15 bytes per pixel, this size works out to around 68,267 pixels — about 302 × 227 px at a 4:3 aspect ratio. Compression varies enormously with image content, so treat this purely as an order-of-magnitude figure.

What to check for this format

WebP uses a RIFF container: the file starts with RIFF and has WEBP at byte 9. It supports lossy, lossless, alpha, and animation — but detecting it from the extension or only the first four bytes risks confusing it with other RIFF-based formats.

• Whether your server-side image library actually supports WebP — older GD or ImageMagick builds may not
• Whether it is served as image/webp — a wrong Content-Type makes browsers download instead of render it
• Whether the JPEG / PNG fallback in your <picture> element works for unsupported clients