A 100 KB WEBP test file

About this file

A 100 KB test file in WEBP format, sized to exactly 102,400 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

100 KB sits at the boundary between "trivially small" and "realistic payload". It is close to the total transfer weight of a single lean web page and is a common target size for performance-conscious images.

It clears the sub-1 MB caps many applications impose, but it is still small enough that a naive load-everything-into-memory implementation works fine — so it is not the right size for proving that streaming is necessary. Pair it with 10 MB or larger to see the difference.

Getting a feel for this size

On a 10 Mbps link the transfer takes roughly 82 ms, and about 8 ms at 100 Mbps. Base64-encoded it grows to roughly 133 KB.

Estimating a photographic WEBP at roughly 0.15 bytes per pixel, this size works out to around 682,667 pixels — about 954 × 716 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