Engineering notes

SnapConv is a local file toolkit that happens to be a website. These are the engineering decisions that keep it private, honest, and fast.

• Static by construction

  The product is a statically exported site. There are no route handlers, server actions, or processing APIs, so there is no server that could receive a file even by accident.

• One registry, one source of truth

  Formats, operations, tool pages, conversion routes, recommendations, and sitemap entries are generated from a typed registry of serializable metadata.

• Measure before promising

  Each tool probes the browser for real decode and encode support — including canvas encoding and lazy WebAssembly codecs — and only advertises the formats that passed. Unavailable codecs are explained instead of silently substituted.

• Verify every result

  Generated files are checked for MIME type, magic-byte signature, and a decode or reopen probe before they are offered for download.

• Bound the work

  A shared scheduler owns concurrency, downgrades resolution when a page or image exceeds the memory budget, cancels deterministically, and disposes canvases, workers, and transferable buffers.

• Test for the browser you have

  Contracts and processors run in unit and real-browser suites, and end-to-end flows run in Chromium, Firefox, and WebKit — including no-egress tests that fail if a selected file ever triggers a network request.