Open source-noter
Every component, self-hosted
FileSlimmer is built almost entirely from open-source software. Each component below is served from this domain — no content delivery network is in the request path — at the exact version recorded here. The licence state of this release was reviewed on 2026-08-16.
This page is the summary. The complete notices, including the transitive licences each codec redistributes, the machine-learning model records and the written offer for corresponding source, are on the open-source notices page.
Bundled libraries
| Component | Version | Licence | Source |
|---|---|---|---|
astro | 7.2.2 | MIT | withastro/astro |
@astrojs/preact | 6.0.2 | MIT | withastro/astro |
preact | 10.29.8 | MIT | preactjs/preact |
@preact/signals | 2.11.1 | MIT | preactjs/signals |
browser-image-compression | 2.0.2 | MIT | Donaldcwl/browser-image-compression |
@jsquash/jpeg | 1.6.0 | Apache-2.0 | jamsinclair/jSquash |
@jsquash/png | 3.1.1 | Apache-2.0 | jamsinclair/jSquash |
@jsquash/oxipng | 2.3.0 | Apache-2.0 | jamsinclair/jSquash |
@jsquash/webp | 1.5.0 | Apache-2.0 | jamsinclair/jSquash |
@jsquash/avif | 2.1.1 | Apache-2.0 | jamsinclair/jSquash |
@jsquash/resize | 2.1.1 | Apache-2.0 | jamsinclair/jSquash |
onnxruntime-web | 1.27.0 | MIT | microsoft/onnxruntime |
pdf-lib | 1.17.1 | MIT | Hopding/pdf-lib |
pdfjs-dist | 6.2.108 | Apache-2.0 | mozilla/pdf.js |
svgo | 4.0.2 | MIT | svg/svgo |
terser | 5.50.0 | BSD-2-Clause | terser/terser |
csso | 5.0.5 | MIT | css/csso |
fflate | 0.8.3 | MIT | 101arrowz/fflate |
mediabunny | 1.54.0 | MPL-2.0 | Vanilagy/mediabunny |
The jSquash packages carry Apache-2.0 for their JavaScript wrappers and redistribute the upstream codec builds under their own terms. Mediabunny is MPL-2.0, which is file-level copyleft; FileSlimmer ships it unmodified, and a modified file would be published under the MPL-2.0 and linked from the notices page.
WebAssembly modules built from LGPL sources
Two modules are compiled from LGPL-licensed sources by FileSlimmer's own reproducible build scripts rather than taken from a published bundle:
| Module | Licence | Build script | Status |
|---|---|---|---|
/wasm/heic/libheif-decode.wasm | LGPL-3.0-or-later | scripts/build-libheif.mjs | Shipped |
/wasm/video/ffmpeg-core.wasm | LGPL-2.1-or-later | scripts/build-custom-ffmpeg.mjs | Not yet shipped |
Both are dynamically loaded WebAssembly files rather than code linked into the application bundle, so a recipient may modify the library, rebuild it with the published script and replace the shipped artifact with their own build. The full written offer for the corresponding source, valid for three years from distribution, is on the open-source notices page.
Reviewed and left out
A licence review can end in a refusal, and these did. None of the packages below is installed in production or served to a browser:
heic2any(MIT) — Upstream bundled-library licence concern around the distributed libheif/libde265 build requires resolution (spec 0.29, 11.3).@imgly/background-removal(AGPL-3.0-or-later) — AGPL-3.0 is incompatible with the intended proprietary distribution (spec 0.24).@ffmpeg/core(LGPL-2.1-or-later WITH inherited component licences) — Standard core distribution exceeds the Cloudflare 25 MiB per-file asset limit and the stricter 24 MiB project budget (spec 0.22, 16.4).
Machine-learning models
Background removal runs a self-hosted ONNX model through ONNX Runtime Web. Model weights are licensed separately from the runtime, each artifact is pinned by hash, and a model is served only after its exact weights file, licence and hash have passed review. The per-model records are on the open-source notices page.
FileSlimmer's own source
The application code itself is not open source. It is published as a static site by ZENIT GROUP S.A.S. under the terms of use; the licences above take precedence over those terms for the components they cover.
Licence questions and requests for corresponding source go to info@zenitgroup.com.co. See the contact page for the rest of what that address handles.
This document is published by ZENIT GROUP S.A.S., Cali, Valle del Cauca, Colombia.