Images · PNG
A 24 MB PNG file, on demand.
Exactly 25,165,824 bytes of a real truecolour PNG with a gradient, not a placeholder rectangle, built on your machine the moment you press the button.
25,165,824 bytes, exactly.
Every byte above the 288 bytes structural minimum goes into a tEXt metadata chunk with a valid CRC, which decoders skip, which is why this file still behaves like one a real user would send.
Unit convention
24 MB on this page means exactly 25,165,824 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 13,981 pages of typed text, 26 minutes of 128 kbps audio, 2 minutes of CD-quality audio, 10 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
Gmail attachment, Cloudflare Free proxy body, GitHub repository 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
Outlook.com attachment, Discord free attachment, AWS API Gateway payload — this exceeds their commonly cited limit, which makes it a useful negative test. Published limits can vary by plan and change over time.
Other PNG sizes
Mail servers and chat apps draw the line in this band — Gmail attachments stop at 25 MB, and plenty of APIs cap request bodies alongside them.
Questions.
Is this 24 MB PNG file valid?
Yes. It is a real truecolour PNG with a gradient, not a placeholder rectangle. The extra bytes sit in a tEXt metadata chunk with a valid CRC, which decoders skip, so it opens in Preview, Photoshop, browsers and Pillow.
Does 24 MB mean 25,165,824 bytes?
On this page, yes — 24 MB uses the binary (MiB) convention, so the file is exactly 25,165,824 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 24 MB file used for?
Mail servers and chat apps draw the line in this band — Gmail attachments stop at 25 MB, and plenty of APIs cap request bodies alongside them. For PNG specifically, the usual job is checking image upload limits, CDN behaviour and thumbnail pipelines.
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.