Build log

Featured build

In production

Eight months in · Still shipping

BlindFile

Send a file up to 500 GB without anyone — including me — being able to read it. Your browser encrypts every chunk before a single byte leaves the machine, the key rides in the URL fragment where the server never sees it, and the whole thing self-destructs after 48 hours.

Encryption

AES-256-GCM, in the browser

Ceiling

500 GB per file

Retention

48 hours, then gone

Runs on

Workers · R2 · D1

Browsers usually give up around 10 GB, so most of the eight months went into the part nobody sees: a streaming upload engine that holds a 499 GB transfer flat at about a gigabyte of RAM. Chunks get read into a reused buffer instead of a fresh one, encryption is quarantined in a Web Worker that gets demolished and rebuilt every six parts, and concurrency is capped by a memory budget rather than a guess. Two earlier fixes made it dramatically worse before that one worked.

Guests send 1 GB with no account at all. A free account gets 5 GB, Pro gets the full 500 GB and zero-knowledge file requests — a public key in a link, so someone can send you something the server still can't read.