MEASURED
The numbers behind Filum.
Every number on this page has a source. No unverified quality claims. No marketing language. Where data is inferred from observable behavior, it says so explicitly.
| Metric | Filum | Context |
|---|---|---|
| Third-party origins per page | 1 | One origin — error and performance telemetry. Nothing in the file path contacts anyone. |
| On-device processing | Yes — every tool | Split, merge, rotate, sign, organize, watermark, crop, redact, page numbers, compress, convert — every tool runs entirely in your browser. Your file never leaves your device. |
| PDF to image output quality | 300 DPI | Pixel-correct output at 300 DPI on standard A4 PDF. |
| Account required | Never | Every tool is available immediately, without registration or sign-up. |
| Number of tools | 46 | Tools span PDF editing, format conversion, and image processing. |
| Files stored permanently | 0 | Your file never reaches a server — every tool processes it locally, in your browser. There is nothing on any server to store, because nothing is ever uploaded. |
Methodology
- Third-party origins per page: Measured 2026-08-10 from the browser's own network log, on cold loads of the homepage and this page: 22 requests on the homepage, 21 of them to filum.se. The one third-party origin is Sentry, which receives an error-and-performance telemetry POST — never any part of your file. This row counts origins rather than requests because the request count is not stable: telemetry can retry or abort on navigation, so a session may show more than one POST to that same single origin. The Geist font is self-hosted at /fonts/ and is first-party; an earlier version of this row called it third-party and counted 2, which was wrong on both counts. Analytics loads only if you accept it, and adds one more origin if you do.
- On-device processing: VERIFIED: tools make zero outgoing requests during operation, confirmed via network panel. There is no server in the file path to upload to or delete from.
- PDF to image output quality: Measured 2026-06-13: pixel width ÷ page width in inches = 300.1 DPI on a standard A4 document. Lossless PNG and JPG outputs both verified.
- Account required: Structural, not sampled: all 46 registry entries run on the in-browser engine, so there is no server call in a conversion to authenticate against. The count above is read from the live registry at build time, and a unit test in the commit and CI gates fails if any entry stops being in-browser.
- Number of tools: Exact count from the live registry — updated automatically when a new tool ships. Each tool is verified on a real document before it appears here.
- Files stored permanently: VERIFIED via network panel: zero file bytes leave the browser during any operation. No server receives, holds, or has visibility into your file.
Claims marked INFERRED are derived from observable behavior, not from source code review. Claims marked VERIFIED were tested directly against production. All numbers represent a point-in-time measurement — the date is stated in each source note.
What this means in practice
On output quality — DPI, format fidelity — Filum is on par with the tools in this category. Where Filum differs is architecture: the operations most likely to involve sensitive documents (sign, redact, crop, organize, split, merge) run locally in your browser. There is nothing to upload and no deletion promise to trust, because nothing was ever sent.
Unlike the rest of this category, Filum runs every tool on your device — even format conversion — so your file is never uploaded to any server at all. The single-origin figure above is the whole story: one third-party receives error and performance telemetry, and nothing in the file path phones home.