Open source licenses

This editor runs entirely in your browser, which means we send you the software rather than run it for you. Everything listed below is third-party work we ship or load, with the licence it is offered under and a link to its source. Licences here were read from each project's own metadata, not from memory.

GPL notice and written offer for source

The export feature is powered by FFmpeg n5.1.4 compiled to WebAssembly and distributed as @ffmpeg/core-mt 0.12.10. That build is configured with --enable-gpl against x264 and x265, so the resulting binary is licensed under the GNU General Public License, version 2 or later. We serve that binary to your browser unmodified, as /vendor/ffmpeg/ffmpeg-core.wasm. We have made no changes to it.

Written offer

The complete corresponding source code for the FFmpeg WebAssembly binary distributed by this site is publicly available at the links below. In addition, ReachUp LTD will, on request, provide the complete corresponding machine-readable source code for that binary on a medium customarily used for software interchange, for no more than our cost of physically performing the distribution. Write to apps@reachuphq.com. This offer is valid for three years from the date this version was distributed.

Shipped to your browser

Served from this origin as part of the application.

Components served to the browser
ComponentVersionLicenceRoleSource
@ffmpeg/core-mt0.12.10GPL-2.0-or-laterMulti-threaded FFmpeg WebAssembly build (ffmpeg-core.wasm) — audio extraction, trimming and exportSource
FFmpegn5.1.4GPL-2.0-or-later (as built)Compiled into ffmpeg-core.wasm with --enable-gpl --enable-libx264 --enable-libx265Source
@ffmpeg/ffmpeg0.12.15MITJavaScript wrapper that drives the FFmpeg WebAssembly coreSource
@ffmpeg/util0.12.2MITHelper utilities for the FFmpeg wrapperSource
onnxruntime-web1.26.0-dev.20260416-b7804b056cMITWebAssembly / WebGPU inference backend for the speech modelsSource
@huggingface/transformers4.2.0Apache-2.0Runs the speech models in the browser (transformers.js)Source
coi-serviceworker0.1.7MITCross-origin-isolation fallback so SharedArrayBuffer stays availableSource
Next.js16.2.12MITApplication frameworkSource
React / React DOM19.2.4MITUI runtimeSource
Tailwind CSS4.3.3MITStylingSource
lucide-react1.27.0ISCIconsSource
zustand5.0.14MITEditor state storeSource
posthog-js1.407.5Apache-2.0 AND MITSelf-hosted, anonymous product analyticsSource
Interserved via next/fontSIL Open Font License 1.1Typeface, self-hosted (no external font request)Source

Compiled into the FFmpeg WebAssembly binary

These libraries are linked into ffmpeg-core.wasm rather than shipped separately. x264 and x265 are the reason the combined binary is GPL rather than LGPL. Versions come from the ffmpeg.wasm build definition; licences from each project's own COPYING file.

Libraries compiled into the FFmpeg binary
ComponentVersionLicenceRoleSource
x264branch 4-coresGPL-2.0-or-laterH.264 encoderSource
x2653.4GPL-2.0-or-laterH.265 encoderSource
LAMEmasterLGPL-2.0-or-laterMP3 encoderSource
libvpxv1.13.1BSD-3-Clause (WebM Project)VP8 / VP9 codecSource
Ogg / Vorbis / Theora / Opus1.3.4 / 1.1.1 / 1.3.1BSD-3-Clause (Xiph.Org)Container and audio/video codecsSource

Speech models

Model weights are downloaded by your browser directly from the Hugging Face CDN the first time you transcribe, and cached there. We never host or redistribute them.

Speech models
ComponentVersionLicenceRoleSource
onnx-community/whisper-base_timestampedONNX export of openai/whisper-baseApache-2.0Speech-to-text with per-word timestampsSource
onnx-community/whisper-small_timestampedONNX export of openai/whisper-smallApache-2.0Speech-to-text, higher accuracySource
onnx-community/pyannote-segmentation-3.0ONNX export of pyannote/segmentation-3.0MITSpeaker segmentation and diarizationSource
onnx-community/silero-vadONNX export of Silero VADMITVoice-activity detectionSource

Upstream project

This editor is a modified fork of Rescript by Wassim Gharbi (@wassgha), used under the MIT License. We rebranded it, removed Google Analytics, changed the hosting model and reworked the interface. The upstream copyright notice and the full MIT permission notice are preserved in the LICENSE and NOTICE.md files that travel with the source.

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