Images · WebP
A 40 MB WebP file, on demand.
Exactly 41,943,040 bytes of a WebP image encoded by your browser, built on your machine the moment you press the button.
41,943,040 bytes, exactly.
Every byte above the 1,309 bytes structural minimum goes into a custom RIFF chunk, with the container size field corrected afterwards, which is why this file still behaves like one a real user would send.
Unit convention
40 MB on this page means exactly 41,943,040 bytes, using the binary (MiB) convention some systems label "MB" for short. 1 MB in the strict decimal sense is 1,000,000 bytes; 1 MiB is 1,048,576 bytes — the readout above always shows the exact count either way.
Approximate size equivalents
Roughly 23,302 pages of typed text, 44 minutes of 128 kbps audio, 4 minutes of CD-quality audio, 17 photos from a 12 MP camera. These figures compare file size only — the generated file does not contain this text, audio or image content.
Accepted by
Cloudflare Free proxy body, GitHub repository file, Slack free workspace file — all publish a limit at or above this size, based on commonly cited figures that can vary by plan and change over time.
Rejected by
Gmail attachment, Outlook.com attachment, Discord free attachment — this exceeds their commonly cited limit, which makes it a useful negative test. Published limits can vary by plan and change over time.
Other WebP sizes
Files this large exercise multipart and chunked upload paths rather than a single request, which is usually where the bugs are.
Questions.
Is this 40 MB WebP file valid?
Yes. It is a WebP image encoded by your browser. The extra bytes sit in a custom RIFF chunk, with the container size field corrected afterwards, so it opens in modern browsers, Photoshop 23+ and libwebp tools.
Does 40 MB mean 41,943,040 bytes?
On this page, yes — 40 MB uses the binary (MiB) convention, so the file is exactly 41,943,040 bytes. 1 MB in the strict decimal sense would be a different, smaller byte count. Upload validators may use either convention, so the exact byte count is always shown to remove any ambiguity.
What is a 40 MB file used for?
Files this large exercise multipart and chunked upload paths rather than a single request, which is usually where the bugs are. For WebP specifically, the usual job is testing next-gen image delivery and format negotiation.
Where is the file downloaded from?
Nowhere. It is assembled in a Web Worker on your own device and handed to the browser as a Blob, so nothing is uploaded, fetched or stored.