A 500 KB GIF test file

About this file

A 500 KB test file in GIF format, sized to exactly 512,000 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

500 KB is a realistic size for a single high-resolution photo. It puts a load close to real-world data on front-end image optimisation and preview-generation paths.

Base64-encoded it grows to roughly 667 KB, because Base64 inflates data by about 33%. If you embed files in data URIs, email attachments, or JSON payloads, your limits must account for that expansion.

Getting a feel for this size

On a 10 Mbps link the transfer takes roughly 410 ms, and about 41 ms at 100 Mbps. Base64-encoded it grows to roughly 667 KB.

Estimating a photographic GIF at roughly 0.5 bytes per pixel, this size works out to around 1,024,000 pixels — about 1,168 × 876 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