Credits and licences
The tools are written for this site, but many stand on open-source work by other people. Every library below is copied onto this site and served from it, never loaded from anyone else’s server, and each keeps its copyright and licence notice at the top of its file or in a licence file beside it. Thank you to everyone who made them.
Libraries
- Asciidoctor.js 4.1.0
- Copyright
- Copyright (C) 2014-present Dan Allen, Guillaume Grossetie, Anthonny Quérouil and the Asciidoctor Project
- Licence
- MIT License
- Source
- github.com/asciidoctor/asciidoctor.js
- Used by
- Markup Converter
- axe-core 4.14.0
- Copyright
- Copyright (c) 2015-2026 Deque Systems, Inc.
- Licence
- Mozilla Public License 2.0
- Source
- github.com/dequelabs/axe-core
- Used by
- Accessibility Check, Package Player
- bcrypt.js 3.0.3
- Copyright
- Copyright (c) 2012 Nevins Bartolomeo, Copyright (c) 2012 Shane Girish, Copyright (c) 2025 Daniel Wirtz
- Licence
- BSD 3-Clause License
- Source
- github.com/dcodeIO/bcrypt.js
- Used by
- Bcrypt
- brotli.js (decoder), with base64-js 1.5.1 1.3.3
- Copyright
- Copyright Devon Govett; Copyright 2013 Google Inc. (the decoder, Apache-2.0); Copyright (c) 2014 Jameson Little (base64-js)
- Licence
- MIT License and Apache License 2.0
- Source
- github.com/devongovett/brotli.js
- Used by
- Font Inspector, Font Converter, Fallback Font Matcher, Parquet Viewer
- brotli.js (encoder), with base64-js 1.5.1 1.3.3
- Copyright
- Copyright Devon Govett; Copyright 2013 Google Inc. (the Brotli encoder and decoder, Apache-2.0); Copyright (c) 2014 Jameson Little (base64-js)
- Licence
- MIT License and Apache License 2.0
- Source
- github.com/devongovett/brotli.js
- Used by
- Font Converter (writing WOFF2)
- Notes
- Bundled with two small changes so it runs in a browser without fetching anything; the file's first comment lists them.
- gifenc 1.0.3
- Copyright
- Copyright (c) 2017 Matt DesLauriers
- Licence
- MIT License
- Source
- github.com/mattdesl/gifenc
- Used by
- Image Convert / Resize, Animated GIF Maker, Frame Grabber, Screen Recorder
- gifuct-js, with js-binary-schema-parser 2.0.3 2.1.2
- Copyright
- Copyright (c) 2015 Matt Way
- Licence
- MIT License
- Source
- github.com/matt-way/gifuct-js
- Used by
- Animated GIF Maker, GIF Frame Extractor
- hyparquet, with hyparquet-compressors 1.1.2 (gzip and LZ4) and fzstd 0.1.1 1.31.3
- Copyright
- Copyright (c) Hyperparam (hyparquet and hyparquet-compressors); Copyright (c) 2020 Arjun Barrett (fzstd); Copyright (c) 2023 Arjun Barrett (the gzip decoder, adapted from fflate)
- Licence
- MIT License
- Source
- github.com/hyparam/hyparquet
- Used by
- Parquet Viewer
- ImageTracer.js 1.2.6
- Copyright
- Public domain, András Jankovics (andras@jankovics.net)
- Licence
- The Unlicense (public domain dedication)
- Source
- github.com/jankovicsandras/imagetracerjs
- Used by
- Image to SVG
- jpegli, with Highway, libjxl's butteraugli and Little CMS 2 commit 031a007 (October 2026)
- Copyright
- Copyright (c) the JPEG XL Project Authors; Highway Copyright Google LLC (Apache-2.0); Little CMS Copyright (c) 1998-2023 Marti Maria Saguer (MIT)
- Licence
- BSD 3-Clause License
- Source
- github.com/google/jpegli
- Used by
- Image Compressor
- Notes
- Built to WebAssembly with a small wrapper (wasm/jpegli/ in the site's repository), with jpegli's copy of libjxl's butteraugli (the tool's second quality measure) and of Little CMS (which converts colours before measuring); every licence is in the folder's LICENSE.txt.
- js-beautify 2.0.3
- Copyright
- Copyright (c) 2007-2018 Einar Lielmanis, Liam Newman, and contributors
- Licence
- MIT License
- Source
- github.com/beautifier/js-beautify
- Used by
- Code Format
- js-yaml 5.4.2
- Copyright
- Copyright (C) 2011-2015 by Vitaly Puzrin
- Licence
- MIT License
- Source
- github.com/nodeca/js-yaml
- Used by
- Every tool page (YAML)
- jsQR 1.4.0
- Copyright
- Copyright Cosmo Wolfe
- Licence
- Apache License 2.0
- Source
- github.com/cozmo/jsQR
- Used by
- QR Code (in browsers that can't read barcodes themselves)
- libavif, with libaom 3.15.2 and libsharpyuv 1.4.2
- Copyright
- Copyright 2019 Joe Drago (libavif); Copyright (c) 2016, Alliance for Open Media (libaom, with the AOM Patent License 1.0); Copyright (c) 2010, Google Inc. (libsharpyuv, BSD-3-Clause)
- Licence
- BSD 2-Clause License
- Source
- github.com/AOMediaCodec/libavif
- Used by
- Image Compressor (AVIF)
- Notes
- Built to WebAssembly with a small wrapper (wasm/avif/ in the site's repository), and fetched only when AVIF is used; the licences, including libaom's patent licence, are in the folder's LICENSE.txt.
- libwebp 1.6.0
- Copyright
- Copyright (c) 2010, Google Inc.
- Licence
- BSD 3-Clause License
- Source
- chromium.googlesource.com/webm/libwebp
- Used by
- Image Compressor (WebP)
- Notes
- Built to WebAssembly with a small wrapper (wasm/webp/ in the site's repository).
- marked 15.0.12
- Copyright
- Copyright (c) 2011-2025, Christopher Jeffrey
- Licence
- MIT License
- Source
- github.com/markedjs/marked
- Used by
- Every tool page (Markdown)
- mozjpeg (libjpeg-turbo with Mozilla's encoder changes) 4.1.5
- Copyright
- Copyright (C)2009-2023 D. R. Commander; Copyright (C)2015 Viktor Szathmáry; Copyright (C) 1991-2020 Thomas G. Lane, Guido Vollbeding. This software is based in part on the work of the Independent JPEG Group.
- Licence
- Independent JPEG Group licence and BSD 3-Clause License
- Source
- github.com/mozilla/mozjpeg
- Used by
- Image Compressor
- Notes
- Built to WebAssembly with a small wrapper (wasm/jpeg/ in the site's repository).
- @noble/hashes 2.4.0
- Copyright
- Copyright (c) 2022 Paul Miller
- Licence
- MIT License
- Source
- github.com/paulmillr/noble-hashes
- Used by
- Hash / Checksum, Bcrypt
- oxipng, with Zopfli (Rust) 0.8.4, libdeflate and the png crate 0.18.1 10.2.1
- Copyright
- Copyright (c) 2016 Joshua Holmer (oxipng); Copyright 2011 Google Inc. and the zopfli-rs contributors (Zopfli, Apache-2.0); Copyright 2016 Eric Biggers, 2024 Google LLC (libdeflate); Copyright (c) 2015 nwin (png)
- Licence
- MIT License and Apache License 2.0
- Source
- github.com/oxipng/oxipng
- Used by
- Image Compressor
- Notes
- Built to WebAssembly together with the site's own colour quantiser (wasm/squeeze/ in the site's repository), with the small Rust libraries they need; every licence and copyright is in the folder's LICENSE.txt.
- pdf-lib 1.17.1
- Copyright
- Copyright (c) 2019 Andrew Dillon; includes tslib, Copyright (c) Microsoft Corporation (0BSD)
- Licence
- MIT License
- Source
- github.com/Hopding/pdf-lib
- Used by
- PDF Pages, PDF Images, PDF Info & Clean, PDF Stamp, Repair PDF, Fill PDF Forms, Sign PDF, Printable Paper, Invoice Maker
- Pele 1.6.0
- Copyright
- Copyright (c) 2026 kepano (Obsidian)
- Licence
- MIT License
- Source
- github.com/obsidianmd/pele
- Used by
- Mermaid Editor
- Notes
- Its dist/pele.global.js, unchanged, global pele. It draws Mermaid text as SVG with its own layout, so diagrams look different from Mermaid's own drawing.
- lamejs, a JavaScript port of LAME 1.2.1
- Copyright
- The LAME project and lamejs's authors
- Licence
- GNU Lesser General Public License
- Source
- github.com/zhuker/lamejs
- Used by
- Audio Trimmer, Loudness Meter and Sound Effect Generator (saving MP3)
- Notes
- Served unchanged, as its own file loaded only when an MP3 is saved.
- Lucide 1.14.0
- Copyright
- Copyright (c) 2026 Lucide Icons and Contributors
- Licence
- ISC License
- Source
- github.com/lucide-icons/lucide
- Used by
- Mermaid Editor, inside Pele
- Notes
- One icon, rotate-ccw, which Pele bundles for its zoom controls' reset button. It ships inside Pele's file, so its licence is in Pele's licence file.
- PDF.js 6.4.299
- Copyright
- Copyright 2023 Mozilla Foundation
- Licence
- Apache License 2.0
- Source
- github.com/mozilla/pdf.js
- Used by
- PDF Images, PDF Text, Compare PDF, Repair PDF, Image to Text (OCR), Photo Censor, Sign PDF
- Notes
- The pdfjs-dist package's legacy/build/pdf.min.mjs and pdf.worker.min.mjs, unchanged, with their licence notice at the top.
- OpenJPEG, inside PDF.js
- Copyright
- Copyright (c) 2002-2014, Universite catholique de Louvain (UCL), Belgium, and the other OpenJPEG authors; wrapper Copyright (c) 2024, Mozilla Foundation
- Licence
- BSD 2-Clause License
- Source
- github.com/uclouvain/openjpeg
- Used by
- PDF Images, PDF Text, Compare PDF, Repair PDF, Image to Text (OCR), Photo Censor, Sign PDF
- Notes
- PDF.js's JPEG 2000 decoder, from pdfjs-dist's wasm/ folder, unchanged, loaded by its worker when a PDF has such images. The folder's LICENSE.txt has every licence.
- JBIG2 decoder from PDFium, inside PDF.js
- Copyright
- Copyright 2014 The PDFium Authors; wrapper Copyright 2026 Mozilla Foundation (Apache-2.0)
- Licence
- BSD 3-Clause License
- Source
- pdfium.googlesource.com/pdfium/
- Used by
- PDF Images, PDF Text, Compare PDF, Repair PDF, Image to Text (OCR), Photo Censor, Sign PDF
- Notes
- PDF.js's decoder for JBIG2, the black-and-white image format of many scanned PDFs, from pdfjs-dist's wasm/ folder, unchanged.
- qcms, inside PDF.js
- Copyright
- Copyright (C) 2009-2024 Mozilla Corporation; Copyright (C) 1998-2007 Marti Maria
- Licence
- MIT License
- Source
- github.com/FirefoxGraphics/qcms
- Used by
- PDF Images, PDF Text, Compare PDF, Repair PDF, Image to Text (OCR), Photo Censor, Sign PDF
- Notes
- PDF.js's colour management, for pages with ICC colour profiles, from pdfjs-dist's wasm/ folder, unchanged.
- qpdf 12.3.2
- Copyright
- Copyright (c) 2005-2021 Jay Berkenbilt; Copyright (c) 2022-2026 Jay Berkenbilt and Manfred Holger
- Licence
- Apache License 2.0
- Source
- github.com/qpdf/qpdf
- Used by
- Protect / Unlock PDF
- Notes
- The program that reads, encrypts and decrypts the PDF, compiled to WebAssembly, unchanged, and run in a worker. Its own AES, SHA-2, MD5 and RC4 are used (no OpenSSL). The folder's LICENSE.txt has every licence.
- pdfstudio 0.4.0
- Copyright
- Fayaz Ahmed (the package's author)
- Licence
- Apache License 2.0
- Source
- github.com/fayazara/pdfstudio
- Used by
- Protect / Unlock PDF
- Notes
- The npm package that builds qpdf for the browser; only its dist/wasm/qpdf.js (the glue for the WebAssembly) and qpdf.wasm are used, unchanged. The idea of a fresh qpdf instance for each job is from its runner.js.
- zlib, inside qpdf
- Copyright
- (C) 1995-2024 Jean-loup Gailly and Mark Adler
- Licence
- The zlib licence
- Source
- zlib.net
- Used by
- Protect / Unlock PDF
- Notes
- Compiled into qpdf's WebAssembly, from Emscripten's ports.
- libjpeg, inside qpdf
- Copyright
- Copyright (C) 1991-2024 Thomas G. Lane, Guido Vollbeding (the Independent JPEG Group)
- Licence
- Independent JPEG Group licence
- Source
- ijg.org
- Used by
- Protect / Unlock PDF
- Notes
- Compiled into qpdf's WebAssembly, from Emscripten's ports. This software is based in part on the work of the Independent JPEG Group.
- QR Code Generator 2.0.4
- Copyright
- Copyright (c) 2009 Kazuhiko Arase
- Licence
- MIT License
- Source
- github.com/kazuhikoarase/qrcode-generator
- Used by
- Every tool page (QR codes)
- Notes
- QR Code is a registered trademark of DENSO WAVE INCORPORATED.
- smol-toml 1.9.0
- Copyright
- Copyright (c) Squirrel Chat et al.
- Licence
- BSD 3-Clause License
- Source
- github.com/squirrelchat/smol-toml
- Used by
- Data Validator, JSON ⇄ YAML ⇄ TOML, JSON to Types, Identify
- sql-formatter 15.9.0
- Copyright
- Copyright (c) 2016-2020 ZeroTurnaround LLC; Copyright (c) 2020-2021 George Leslie-Waksman and other contributors; Copyright (c) 2021-present inferrinizzard and other contributors
- Licence
- MIT License
- Source
- github.com/sql-formatter-org/sql-formatter
- Used by
- Code Format
- sql.js (SQLite compiled to WebAssembly) 1.14.2
- Copyright
- Copyright (c) 2017 sql.js authors; SQLite itself is in the public domain
- Licence
- MIT License
- Source
- github.com/sql-js/sql.js
- Used by
- SQLite Viewer
- Notes
- Its worker build (`worker.sql-wasm.js` and `sql-wasm.wasm`), served unchanged; the licence is beside them.
- SSIMULACRA 2 (Rust), with v_frame and yuvxyb 0.5.1
- Copyright
- Copyright (c) 2022, the rav1e contributors; yuvxyb Copyright (c) 2022 Josh Holmer (MIT)
- Licence
- BSD 2-Clause License
- Source
- github.com/rust-av/ssimulacra2
- Used by
- Image Compressor
- Notes
- Part of squeeze.wasm (see oxipng); it scores how close each compressed image is to the original.
- SVGO 4.1.0
- Copyright
- Copyright (c) Kir Belevich
- Licence
- MIT License
- Source
- github.com/svg/svgo
- Used by
- Code Format, Image to SVG
- Terser 5.51.2
- Copyright
- Copyright 2012-2018 (c) Mihai Bazon
- Licence
- BSD 2-Clause License
- Source
- github.com/terser/terser
- Used by
- Code Format
- Tesseract.js, with tesseract.js-core 7.0.0 and Tesseract's trained language data (4.0.0_best_int) 7.0.0
- Copyright
- The Tesseract.js and Tesseract OCR authors
- Licence
- Apache License 2.0
- Source
- github.com/naptha/tesseract.js
- Used by
- Image to Text (OCR)
- Notes
- Served unchanged apart from source-map comments; the licence is beside them.
- Turndown, with turndown-plugin-gfm 1.0.2 7.2.4
- Copyright
- Copyright (c) 2017 Dom Christie
- Licence
- MIT License
- Source
- github.com/mixmark-io/turndown
- Used by
- Markup Converter
Fonts and data
- Montserrat
- Copyright
- Copyright 2011 The Montserrat Project Authors
- Licence
- SIL Open Font License 1.1
- Source
- github.com/JulietaUla/Montserrat
- Used by
- The site's headings (a Latin subset of weights 500 to 600)
- Dancing Script 5.3.0
- Copyright
- Copyright 2016 The Dancing Script Project Authors
- Licence
- SIL Open Font License 1.1
- Source
- github.com/googlefonts/DancingScript
- Used by
- Sign PDF and Signature Maker (typed signatures)
- Notes
- The Latin, weight 400 WOFF2 from @fontsource/dancing-script 5.3.0, unchanged.
- EFF Long Wordlist
- Copyright
- Electronic Frontier Foundation
- Licence
- Creative Commons Attribution 3.0 United States
- Source
- eff.org/dice
- Used by
- Password Generator (passphrases); the words only
- SCOWL (Spell Checker Oriented Word Lists), size 60, 2020.12.07
- Copyright
- Copyright 2000-2018 by Kevin Atkinson and the other copyright holders named in its licence
- Licence
- SCOWL's licence (permissive; it must travel with the list)
- Source
- wordlist.aspell.net/
- Used by
- Anagram Solver, Crossword Helper; lowercase words only, with some single letters and letter plurals removed
- Unicode confusables data
- Copyright
- Copyright © 1991-2026 Unicode, Inc.
- Licence
- Unicode License v3
- Source
- unicode.org/Public/security/latest/confusables.txt
- Used by
- Lookalike Characters (the Latin lookalikes, from Unicode's confusables list)
- PubChem periodic table
- Credit
- PubChem (National Library of Medicine, US National Institutes of Health); the facts only, no descriptive text
- Licence
- No licence stated (a compilation of physical facts)
- Source
- pubchem.ncbi.nlm.nih.gov/periodic-table/
- Used by
- Periodic Table
- Notes
- Made by scripts/periodic-data.py from PubChem's periodic table. PubChem states no licence for it and facts aren't copyrightable.
- Hexahue
- Credit
- Hexahue was created by Josh Cramer; the chart follows dCode's
- Licence
- No licence needed (a cipher alphabet)
- Source
- dcode.fr/hexahue-cipher
- Used by
- Picture Alphabets
- Tailwind CSS default colour palette 4.1.14
- Copyright
- Tailwind Labs, Inc.
- Licence
- MIT License
- Source
- github.com/tailwindlabs/tailwindcss
- Used by
- Colour Converter (the nearest Tailwind colour and the Tailwind theme output)
- Notes
- The 22 colour families in 11 steps, as OKLCH values from Tailwind's theme.css, copied into assets/js/images.js; no file of its own.
MIT License
The text of the licence, for the libraries above that use it, each with its own copyright line.
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
BSD 2-Clause License
The text of the licence, for the libraries above that use it, each with its own copyright line.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
BSD 3-Clause License
The text of the licence, for the libraries above that use it, each with its own copyright line.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. 3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Trademarks
Names of products and companies mentioned on this site belong to their owners and are used only to say what a tool works with. The site isn’t affiliated with or endorsed by any of them: see About.