Case study  /  Product build, own

Know what a file really is before it burns you

Born from a real prepress incident: a file that looked fine and was not. DropCheck tells you what a file actually is, where it will break, and what it is leaking, without it ever leaving your machine.

Live, in-browser
  • 100% client-side
  • Nothing uploads
  • Range-read forensics
Try it live →
DropCheck case study card

The engagement

Challenge

A file that looks fine can be the one that breaks the run

A file that looks fine can carry the flaw that breaks a print run or quietly leaks metadata. And you often cannot send a sensitive file to a server to find out what is wrong with it. The check has to happen locally, on files that may be large.

Action

Forensics that never leaves the browser

An in-browser forensics tool with a framework-free core designed to be extracted as a standalone package, range-reads only so a 500 MB file costs a few MB of memory, and a hard privacy invariant: nothing uploads, every parse and fix runs client-side.

Result

Drop a file, learn the truth, at zero privacy cost

Drop a file and learn what it really is, where it will break, and what it leaks, with the privacy guarantee as the product, not a setting. A real static build exists.

How it is built

The privacy guarantee is the architecture

Drop a file
stays on your machine
client-side parse→
Range-read forensics
framework-free core
findings→
What it is, what it leaks
plain-English findings

There is no upload step to remove, because there is no server. That is the whole design.

  • 01Framework-free core. The forensics core has no framework or DOM dependency, so it lifts out as a standalone package.
  • 02Range reads. A RangeReader over Blob.slice never loads a whole large file; a 500 MB PSD costs a few MB of memory.
  • 03Per-format analyzers. Marker walks for JPEG, PSD, and TIFF that surface real verdicts, not trivia.
  • 04Privacy invariant. Nothing transmits file bytes or metadata off the machine, ever. The guarantee is the product.
  • 05Honesty. A published known-limitations list; when a scan is capped, the UI says so.

What it proves

The privacy guarantee is the product: forensics that never sees a server.

See the rest of the work →

Built from a real prepress incident, described here in the abstract with no client or file detail.