Data · JSON
A 200 MB JSON file, on demand.
Exactly 209,715,200 bytes of a valid JSON document with a records array, built on your machine the moment you press the button.
209,715,200 bytes, exactly.
Every byte above the 60 bytes structural minimum goes into a trailing string field, so the document still parses, which is why this file still behaves like one a real user would send.
Unit convention
200 MB on this page means exactly 209,715,200 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 116,508 pages of typed text, 218 minutes of 128 kbps audio, 20 minutes of CD-quality audio, 84 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
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
Cloudflare Free proxy body, GitHub repository file, Gmail 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 JSON sizes
At this scale you are testing infrastructure rather than validation: timeouts, proxy buffers, disk headroom and progress reporting.
Questions.
Is this 200 MB JSON file valid?
Yes. It is a valid JSON document with a records array. The extra bytes sit in a trailing string field, so the document still parses, so it opens in jq, browser devtools, Python's json module and Node's JSON.parse.
Does 200 MB mean 209,715,200 bytes?
On this page, yes — 200 MB uses the binary (MiB) convention, so the file is exactly 209,715,200 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 200 MB file used for?
At this scale you are testing infrastructure rather than validation: timeouts, proxy buffers, disk headroom and progress reporting. For JSON specifically, the usual job is testing API payload limits and request body caps.
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.