Clean Viewer Open Source Notices

The web viewer (clean-viewer.vercel.app/view) hosts the open source components below on this site unmodified, as originally released. Each component is downloaded from this site only when you use that feature, and it does not connect anywhere else. The full license text is linked next to each component. 한국어

PDF.js 6.3.289

• Used for: viewing PDFs
• Author: Mozilla Foundation · License: Apache License 2.0 — full license

Tesseract.js 5.1.1 · Tesseract training data (tessdata_best 4.0.0)

• Used for: "Read text" in scanned PDFs and photos
• License: Apache License 2.0 — Tesseract.js license · tesseract.js-core license

libheif-js 1.23.2 (libheif · libde265)

• Used for: viewing iPhone photos (HEIC) in Chrome, Edge and similar browsers (not used in Safari)
• License: GNU Lesser General Public License 3.0 (LGPL-3.0) — libheif-js full license · libheif license notice
• Source: github.com/catdad-experiments/libheif-js · github.com/strukturag/libheif — the file on this site (libheif-bundle.mjs) is identical to that version's release. Under the LGPL it is kept as a separate file so it can be replaced with another version.

Unicode CLDR time zone names (windowsZones)

• Used for: mapping Windows time zone names in Outlook calendar files (.ics) to regional time zones (the table only)
• Author: Unicode, Inc. · License: Unicode License v3 — full license
• Source: github.com/unicode-org/cldr (common/supplemental/windowsZones.xml)

UTIF.js 3.1.0

• Used for: opening scanner and fax images (TIFF) — downloaded only when you open a TIFF
• Author: Photopea (Ivan Kutskir) · License: MIT License — full license
• Source: github.com/photopea/UTIF.js

jsQR 1.4.0

• Used for: reading QR codes in photos and PDFs — downloaded only when the browser cannot read them itself
• Author: Cosmo Wolfe · License: Apache License 2.0 — full license
• Source: github.com/cozmo/jsQR

Public specifications

Hangul distribution documents, Word, Excel and PowerPoint (including the older formats), OpenDocument, RTF and email files are read by code written for this site, following the public specifications (Microsoft Open Specifications · OASIS ODF · RFC 5322·2045 · Zstandard RFC 8878 and others). JPEG 2000 images inside TIFF are drawn with OpenJPEG, which comes with PDF.js above.

PPMd and BCJ2 decoding for 7z archives ports the algorithms (Ppmd7·Bcj2) of 7-Zip's LZMA SDK (Igor Pavlov · public domain — 7-zip.org/sdk) into this site's code.

Reversing the RISC-V and IA-64 executable filters in xz and 7z archives ports the algorithms in src/liblzma/simple/riscv.c·ia64.c of XZ Utils (Lasse Collin and others · liblzma is under the 0BSD license — tukaani.org/xz) into this site's code (xzfilter.js).

LibreOffice hwpfilter

• Used for: mapping Hanja and symbol character codes of old Hangul documents (before Hangul 97 · format 3.0) to KS X 1001 positions, the symbol table (64 cells) and the meaning of paragraph alignment values — the algorithms were ported into this site's code (hwp3.js); characters are converted with the browser's EUC-KR decoder
• Author: The Document Foundation (LibreOffice) · License: Mozilla Public License 2.0 — full license
• Source: github.com/LibreOffice/core — hwpfilter/source (hcode.cxx · hwpreader.cxx)

LibreOffice libvisio

• Used for: spline curves (SplineStart·SplineKnot) in Visio drawings (.vsdx) — the knot filling and curve splitting algorithms were ported into this site's code (vsdx.js); the specification does not say how to fill them, so they are drawn the way LibreOffice draws them
• Author: The Document Foundation (LibreOffice) · License: Mozilla Public License 2.0 — full license
• Source: github.com/LibreOffice/libvisio (src/lib/VSDContentCollector.cpp · VSDXMLParserBase.cpp)

libarchive (RAR reading)

• Used for: unpacking "RAR compression" in RAR archives (.rar) and RAR comic books (.cbr) — the LZSS, Huffman table and PPMd block switching algorithms of the RAR 3.x·4.x format (unpack version 29) were ported into this site's code (rar29.js); RAR4 filters and RAR5 compression were not ported. The PPMd model and RAR-style range decoding come from the LZMA SDK above (public domain)
• Author: Tim Kientzle · Andres Mejia (libarchive) · License: BSD 2-Clause License — Copyright (c) 2003-2007 Tim Kientzle · Copyright (c) 2011 Andres Mejia. All rights reserved. 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 AUTHOR(S) ``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 AUTHOR(S) 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.
• Source: github.com/libarchive/libarchive (libarchive/archive_read_support_format_rar.c)

libazo · unegg

• Used for: AZO (ALZip-only compression) decoding in Bandizip·ALZip (EGG) archives and the structure of LEA decryption (key setup · counter) — the algorithms were ported into this site's code (azo.js · arccrypt.js)
• Author: Sungjoon Moon · License: MIT License — Copyright (c) 2026 Sungjoon Moon. 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.
• Source: github.com/alkegi/libazo · github.com/alkegi/unegg · the LEA block cipher is the public standard KS X 3246

ezdxf

• Used for: the hatch pattern table for CAD drawings (.dxf) — when a drawing names a pattern (ANSI31·NET·BRICK and so on) without defining it, ezdxf's pattern table (tools/_iso_pattern.py · 172 patterns) was moved into this site's hatchpat.js so it can be drawn in that shape
• Author: Manfred Moitzi · License: MIT License — Copyright (c) 2020 Manfred Moitzi. 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.
• Source: github.com/mozman/ezdxf (src/ezdxf/tools/_iso_pattern.py)

Google Play services document scanner (ML Kit) — Android app

• Used for: "Scan" in the Android app — Google Play services shows the capture screen (edge detection · straightening). Captured photos are processed on the phone and are not sent to a server. On phones without Play services, the phone's camera app is used instead
• Author: Google · Not open source; governed by the ML Kit Terms of Service (play-services-mlkit-document-scanner 16.0.0)