A 10 MB GIF test file

About this file

A 10 MB test file in GIF format, sized to exactly 10,485,760 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 MB is one of the most common "round number" caps chosen for forms and CMS uploads. It is exactly 10,485,760 bytes (10 × 1024 × 1024), which also lets you detect whether an implementation computes MB with 1000 or with 1024.

An implementation using 1000 rejects anything past 10,000,000 bytes, so this file fails there. One using 1024 accepts it as exactly at the limit. To pin down the boundary precisely, combine it with the threshold set (9.9 MB / 10.0 MB / 10.1 MB).

Getting a feel for this size

On a 10 Mbps link the transfer takes roughly 8.4 seconds, and about 839 ms at 100 Mbps. Base64-encoded it grows to roughly 13,653 KB.

Estimating a photographic GIF at roughly 0.5 bytes per pixel, this size works out to around 20,971,520 pixels — about 5,288 × 3,966 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