Day Zero · Offline kit
Keep the essentials offline
If the services you rely on stop working, these files keep working. Each one comes from its publisher's own server and always points to the newest release. We check every source daily; most publish a new version each month, so come back once a week and refresh what changed.
Custodians of human knowledge
If the internet were gone, could people rebuild?
This list is built for that day: the sciences, engineering, aerospace, computing, medicine, farming and the tools to read it all. Anyone can keep a copy. We ask people who take on the role of custodian to do three things every month.
- Download the whole kit. Everything marked Download, and the data pages you can afford to hold. Start with the essentials if space is short.
- Keep two copies in two places. One at home, one with someone you trust, each on a drive stored dry and away from power surges. Check the SHA-256 of every file.
- Refresh it each month. Replace what has a newer release, test that a few pages open with no internet, and rotate the drives every few years.
How to use the kit
- Get a drive. A 32 GB USB stick holds the essentials; the complete set needs several terabytes, so spread it over more than one drive.
- Install Kiwix. The reader opens every .zim file here without internet, on a computer or a phone.
- Refresh weekly. This page remembers what you downloaded on this device and marks what has a newer release.
Knowledge
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Wikipedia in English, completeNew release
Every article with images. The largest single store of general knowledge you can keep offline.
Check the file
SHA-256
34162d18b9f96f494eac48a73a309c72e0bc95d85f76be405d0f5de795854aa6Compare it with the output of
shasum -a 256 wikipedia_en_all_maxi_2026-08.zimafter the download. -
Wikipedia in English, text onlyNew release
Every article without images, at less than half the size.
Check the file
SHA-256
441a56d9e05b2d98f8ae9acb7986a513ed47904d73852c92dc6b7d50baa122e5Compare it with the output of
shasum -a 256 wikipedia_en_all_nopic_2026-06.zimafter the download. -
Wikipedia in English, short editionEssentialNew release
The introduction of every article. Fits on a phone.
Check the file
SHA-256
350d8956ee3d7abe2839c464c3a983f93d6934a16c7f04b10715b49439dfd349Compare it with the output of
shasum -a 256 wikipedia_en_all_mini_2026-09.zimafter the download. -
Wikipedia in Persian, completeNew release
Every Persian article with images.
Check the file
SHA-256
65f33c421fc3d4bd2c17d8357a7d8e251860bae30847db35db506daceb30cccdCompare it with the output of
shasum -a 256 wikipedia_fa_all_maxi_2026-10.zimafter the download. -
Wiktionary in EnglishNew release
Dictionary with definitions, pronunciation and translations.
Check the file
SHA-256
5276f63a2e451518ec5b7c4452ca9a4f72fae48991da3fe7ebc47df74bae760aCompare it with the output of
shasum -a 256 wiktionary_en_all_nopic_2026-08.zimafter the download. -
Wikibooks in EnglishNew release
Open textbooks on mathematics, science, engineering, languages and cooking.
Check the file
SHA-256
c2ded9afe4647c2b05aceb9d30260100369cbba22f3d00e467a634546da3f610Compare it with the output of
shasum -a 256 wikibooks_en_all_maxi_2026-04.zimafter the download. -
Project Gutenberg in EnglishNew release
Tens of thousands of public-domain books, from literature to old technical manuals.
Check the file
SHA-256
01677c8d554a1cab2cbfd020ac99ebca7dd6c74d3ce0d13f266a2ba603dfaf28Compare it with the output of
shasum -a 256 gutenberg_en_all_2025-11.zimafter the download. -
Wikiversity in EnglishNew release
Free university-level courses and learning projects across the sciences.
Check the file
SHA-256
f2667509251c1784270c8c8dd0cd8a79d438a5c4940a6cc70653a6f77318a421Compare it with the output of
shasum -a 256 wikiversity_en_all_maxi_2026-05.zimafter the download. -
Wikisource in EnglishNew release
Primary texts and source documents: laws, treatises, classic scientific works.
Check the file
SHA-256
e708fde1d8f69f40caba4c6840e7a8dcccbd20a0eedc9a84b461108aae096a74Compare it with the output of
shasum -a 256 wikisource_en_all_maxi_2026-09.zimafter the download.
Science and engineering
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Wikipedia: physicsNew release
Every physics article with images, from mechanics to quantum field theory.
Check the file
SHA-256
60526d45903c1c390b0e969e3a7214c627043835dd565ae1658cc881935f246dCompare it with the output of
shasum -a 256 wikipedia_en_physics_maxi_2026-07.zimafter the download. -
Wikipedia: chemistryNew release
Elements, compounds, reactions and industrial processes.
Check the file
SHA-256
06adce3879a5d5e109f2c4089ff5a7d92afa89024f498f90c5f2555dd14d8d44Compare it with the output of
shasum -a 256 wikipedia_en_chemistry_maxi_2026-07.zimafter the download. -
Wikipedia: mathematicsNew release
Mathematics from arithmetic to advanced analysis and statistics.
Check the file
SHA-256
069b5c59f508d795f223e91e875190007e5d9ac23681cf07cfb72ee6d64d5793Compare it with the output of
shasum -a 256 wikipedia_en_mathematics_maxi_2026-09.zimafter the download. -
Physics Stack ExchangeNew release
Questions and worked answers from working physicists.
Check the file
SHA-256
440e50c991709012e7436e2a965566fee61f118ff9e98d1ce44961d162e1a753Compare it with the output of
shasum -a 256 physics.stackexchange.com_en_all_2026-08.zimafter the download. -
Mathematics Stack ExchangeNew release
Proofs, methods and explanations at every level.
Check the file
SHA-256
9b06975bba543aa5fd4a0ff82497349c061aacde394a0d2120c6898271063238Compare it with the output of
shasum -a 256 math.stackexchange.com_en_all_2026-08.zimafter the download. -
Chemistry Stack ExchangeNew release
Laboratory and theoretical chemistry answered by chemists.
Check the file
SHA-256
bc99e888d3d9e02eddd470b9a00e351c00436c79b039ee6c4009905160f280ddCompare it with the output of
shasum -a 256 chemistry.stackexchange.com_en_all_2026-07.zimafter the download. -
Electronics Stack ExchangeNew release
Circuits, power, radio and embedded hardware from practising engineers.
Check the file
SHA-256
5a23c08a3c1275128c247b0c67ec8ed03a953a504c6a23e2cd6a9ac5422b88c1Compare it with the output of
shasum -a 256 electronics.stackexchange.com_en_all_2026-08.zimafter the download. -
Engineering Stack ExchangeNew release
Mechanical, civil and materials engineering questions and answers.
Check the file
SHA-256
c0260aea6bd6c4b9508bcae4540400df0593ea321a588aa0f85ea4b26fada93fCompare it with the output of
shasum -a 256 engineering.stackexchange.com_en_all_2026-08.zimafter the download. -
Biology Stack ExchangeNew release
Biology from cells to ecosystems, answered by biologists.
Check the file
SHA-256
e195995da99e219251316d7ca6ebc7698558032ed17f32de9cb95ea0a6e9ee68Compare it with the output of
shasum -a 256 biology.stackexchange.com_en_all_2026-07.zimafter the download. -
LibreTexts: chemistryNew release
Complete open university chemistry textbooks.
Check the file
SHA-256
83ba2fbfe36d72abe919661de5548103bb6674749bc26531cd61f83d8a825764Compare it with the output of
shasum -a 256 libretexts.org_en_chem_2025-01.zimafter the download. -
LibreTexts: physicsNew release
Complete open university physics textbooks.
Check the file
SHA-256
ace498581e085093cc86383439342d9ff5a4604bd87f6b82448c019e1264830fCompare it with the output of
shasum -a 256 libretexts.org_en_phys_2026-01.zimafter the download. -
LibreTexts: engineeringNew release
Open engineering textbooks: statics, thermodynamics, circuits, materials.
Check the file
SHA-256
3d4b25d03082172f4793625163b366a7d21655a5f8868d0758a9c3649ce9d5c2Compare it with the output of
shasum -a 256 libretexts.org_en_eng_2025-01.zimafter the download. -
PhET interactive simulationsNew release
Physics, chemistry and biology simulations that run in a browser with no internet.
Check the file
SHA-256
b102abf8af1c982c498c167efe6a9099e3cb543df184b93c99421b2fdef7e1a0Compare it with the output of
shasum -a 256 phet_en_all_2026-08.zimafter the download. -
OpenStax university textbooks
Free peer-reviewed textbooks in physics, chemistry, biology, mathematics and engineering, as PDFs.
Aerospace and space
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Space Exploration Stack ExchangeNew release
Orbital mechanics, launch vehicles, spacecraft design and mission history.
Check the file
SHA-256
c1a644c3bb4d3d20a183b6d67c99037a57e7a48c4f82520f16eb327f8a92c37aCompare it with the output of
shasum -a 256 space.stackexchange.com_en_all_2026-08.zimafter the download. -
Aviation Stack ExchangeNew release
Aerodynamics, aircraft systems, propulsion and flight operations.
Check the file
SHA-256
7e8ee394dfc3d0d79e32fc8629db6d58fc83b78be0506a5c65625a57d3a050aeCompare it with the output of
shasum -a 256 aviation.stackexchange.com_en_all_2026-07.zimafter the download. -
Astronomy Stack ExchangeNew release
Astrophysics, observation and celestial mechanics.
Check the file
SHA-256
48bc48a3727bb9d9dbdb66e5c9b217c5b359b04b355bd7d4ae2b99c8bdf981f9Compare it with the output of
shasum -a 256 astronomy.stackexchange.com_en_all_2026-07.zimafter the download. -
NASA Technical Reports Server
Millions of NASA reports on aeronautics, propulsion, materials and spaceflight. Download the reports you need.
Computing and software
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Wikipedia: computingNew release
Computer science, hardware, networks and software articles.
Check the file
SHA-256
fbaade6136c2e1d3d49b6fc74bedf1bd669ccaa344bd38aa10a9da505e523653Compare it with the output of
shasum -a 256 wikipedia_en_computer_maxi_2026-09.zimafter the download. -
Computer Science Stack ExchangeNew release
Algorithms, complexity, compilers and theory.
Check the file
SHA-256
8b512ce95788a3d54b53c67984f83147a135ece055e38bd5b3d0d5df17b6a13aCompare it with the output of
shasum -a 256 cs.stackexchange.com_en_all_2026-07.zimafter the download. -
Software Engineering Stack ExchangeNew release
How to design, build and maintain software.
Check the file
SHA-256
85e991529f022e029c2ce6cc1c209e556e09dac7d6f4ae979d46d310b9fd8e48Compare it with the output of
shasum -a 256 softwareengineering.stackexchange.com_en_all_2026-08.zimafter the download. -
Unix and Linux Stack ExchangeNew release
Operating system administration and the command line.
Check the file
SHA-256
738326e81abe0f50edbaa3e4a002d0ca221e5dfb66e4954bb64e370756f602d3Compare it with the output of
shasum -a 256 unix.stackexchange.com_en_all_2026-08.zimafter the download. -
Stack OverflowNew release
The largest archive of programming questions and answers. Very large.
Check the file
SHA-256
2878fd0bbc4d0d7a05249bc04f45b71f183c09929a843308b923190f1d15436fCompare it with the output of
shasum -a 256 stackoverflow.com_en_all_2026-07.zimafter the download. -
Debian install images
A complete operating system and tens of thousands of programs with source code, installable with no internet.
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Software Heritage archive
The universal archive of public source code. Browse and download the repositories you need.
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Python documentation
The language reference, standard library and tutorials as HTML or PDF.
Health and first aid
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Medical Sciences Stack ExchangeNew release
Clinical and biomedical questions answered by professionals.
Check the file
SHA-256
cdf4bfa36ba2142fe3ec0d19d7c08486a0d121f55b9c44f7f5adbfb748d6cbadCompare it with the output of
shasum -a 256 medicalsciences.stackexchange.com_en_all_2026-02.zimafter the download. -
Hesperian health guides
Where There Is No Doctor, Where Women Have No Doctor and other free guides written for communities with no clinic.
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WikiMed medical encyclopediaEssentialNew release
Wikipedia's medical articles: diseases, drugs, anatomy and first aid.
Check the file
SHA-256
6f67340a7cd7665bb57c27d2bbff97e26f2037477c9ea597345a118286820331Compare it with the output of
shasum -a 256 wikipedia_en_medicine_maxi_2026-04.zimafter the download. -
WikEM emergency medicineNew release
Clinical reference written by emergency doctors.
Check the file
SHA-256
7bbdd705544616df1ff37f8b4e0e5382e7b4d92532feecea42227af4169fbd7fCompare it with the output of
shasum -a 256 wikem_en_all_maxi_2026-07.zimafter the download.
Practical skills
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Home Improvement Stack ExchangeNew release
Building, plumbing, electrical work and repairs.
Check the file
SHA-256
94cbd4daeebe180bb8908b767d3c1477753049a29c2c092f6a752b6f691863daCompare it with the output of
shasum -a 256 diy.stackexchange.com_en_all_2026-08.zimafter the download. -
Gardening Stack ExchangeNew release
Growing food: soil, seeds, pests and seasons.
Check the file
SHA-256
b8a3e0db65d8a678b47accefd8565f78af0caeb454672fe0d5f365336c71c25eCompare it with the output of
shasum -a 256 gardening.stackexchange.com_en_all_2026-08.zimafter the download. -
Amateur Radio Stack ExchangeNew release
Building and operating radios when networks are down.
Check the file
SHA-256
71480bd280ffaede3084fa2c9f47f87c3178f8ce8d67cdb19fb66a8025a7b93eCompare it with the output of
shasum -a 256 ham.stackexchange.com_en_all_2026-08.zimafter the download. -
iFixit repair guidesEssentialNew release
Step-by-step repair guides for phones, computers, appliances, cars and tools.
Check the file
SHA-256
9bb5f3408707fd0300c6ef47a425c3217187f144cd9154a928183816aa72eeadCompare it with the output of
shasum -a 256 ifixit_en_all_2025-12.zimafter the download. -
AppropediaNew release
Water, sanitation, energy, farming and building with local means.
Check the file
SHA-256
dcf200ba723c27397e1c9a2e4891ff91fa13993df1fa285315190d8525a53469Compare it with the output of
shasum -a 256 appropedia_en_all_maxi_2026-02.zimafter the download. -
Wikivoyage in EnglishNew release
Travel guides for every country and city: transport, health, safety.
Check the file
SHA-256
ebaf235b4f95aa7f8666e0a613578577569eb6c81562ebcf397a7ba52173c848Compare it with the output of
shasum -a 256 wikivoyage_en_all_maxi_2026-09.zimafter the download.
Maps
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OpenStreetMap by region
Full map data for any continent or country, updated every day. Pick your region on the publisher's page.
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Organic Maps
Free offline map and navigation app for phones. Download your country's map inside the app.
Reference data
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arXiv preprints
The papers of physics, mathematics, computer science and biology. Bulk access for archivists; very large.
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PubMed Central open access papers
Millions of full-text biomedical papers that may be downloaded in bulk.
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PubChem
Chemical structures, properties and safety data for over a hundred million compounds.
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UniProt protein database
Sequences and functions of proteins across all life.
Apps to open the files
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Kiwix readerEssential
Opens the .zim files above on Windows, macOS, Linux, Android and iPhone, with no internet.
TOSWO hosts none of these files. Every download goes straight to the publisher, under the publisher's licence. Large files may take hours; if a download stops, the torrent link resumes where it left off. Keep the drive somewhere dry, and test it once a month by opening a few pages without internet.