A 100 KB GIF test file

About this file

A 100 KB test file in GIF 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 GIF at roughly 0.5 bytes per pixel, this size works out to around 204,800 pixels — about 523 × 392 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

GIF begins with the ASCII signature GIF87a or GIF89a and uses a palette of up to 256 colours. Because it can hold multiple animation frames, code written for single-frame images either grabs only the first frame or, worse, expands every frame and consumes far more memory than expected.

• Whether resizing an animated GIF preserves the animation or flattens it to a still
• Whether thumbnail generation correctly extracts the first frame
• Whether you cap memory when expanding all frames — usage grows with frame count multiplied by resolution