About Omnipedia

What is Omnipedia?

Omnipedia is an offline encyclopedia app that lets you read high-quality articles without an internet connection. It’s designed for anyone who wants fast access to the world’s knowledge – even in remote or low-connectivity environments. It’s great for all those random moments when you don’t have internet access.

To make this possible, we compress all articles available on Wikipedia into a compact archive that will fit comfortably on your device. We do this in full compliance with Wikipedia’s Creative Commons license, and while access to Omnipedia is only available on a subscription basis, the content itself remains free to use, share, and adapt under the same terms.

Why pay for Omnipedia, when Wikipedia is free?

We strongly support Wikipedia’s mission of free knowledge for everyone. What Omnipedia offers is an enhanced way to use Wikipedia’s rich content: offline access, private on-device search, personalized article recommendations, and a mobile-friendly reading experience. Our goal is to increase the freedom of Wikipedia articles by making them available in even more places, at even more times, and to even more people. Our subscription fees support the development and maintenance of this enhanced experience.

Who runs Omnipedia?

Omnipedia is made by Recursive Ink, a small independent developer based in the UK. You can contact us in the app or by emailing omnipedia@recursive.ink.

Do you collect any personal data?

We do not routinely collect any personal information, even if you are a subscriber. We also do not collect any information or statistics about what you search for, what articles you read, or how you use the app. Your bookmarks and reading history remain on your device and you can rest assured that you will always have a completely private reading experience.

We do keep some logs of library downloads and updates, and we temporarily log your IP address during the download process. However, we only use this information for normal service provision and it is not directly linked to your identity. Additionally, Apple provides us with some general statistics, such as the number of downloads and subscriptions from each country; but, again, such statistics are not linked to you personally.

You can find more information in our Privacy Policy.

Subscriptions

How much does Omnipedia cost?

We offer a single annual subscription plan – no confusing tiers, annoying upsells, or hidden charges. See the Subscription section of the app for pricing in your region and currency.

Can I try the app before purchasing a subscription?

Yes. The Omnipedia app is free to download and comes bundled with a demo library of 100 articles so that you can quickly try it out. The demo has no time limit – you can use it for as long as you like. Once subscribed, you can download complete libraries containing millions of articles.

Why does Omnipedia require a subscription?

We think subscription-based pricing makes sense for three reasons:

  1. Omnipedia libraries are complex to create and maintain, and they are costly to store and distribute over the internet. Subscription revenue allows us to cover these ongoing costs in a way that is sustainable.
  2. Subscriptions keep us accountable to you and ensure that our interests are always aligned with yours. We do not make decisions based on short-term profiteering or the interests of advertisers.
  3. With ongoing revenue, we can continue to improve the Omnipedia app to give you an excellent reading experience that stays up-to-date with the latest features of iOS and continues to work on the newest devices.

Can I still use Omnipedia if I decide not to renew my subscription?

Yes. The libraries that you’ve already downloaded to your device will continue to work indefinitely. However, if you do cancel your subscription, you will no longer have access to library updates, so the articles on your device will gradually become stale and inaccurate over time. In addition, you will not be able to re-download a library, which may be a problem if you upgrade to a new device or if you want to temporarily remove the library to free up some space. In cases such as these, you will need to make your own backup. See the Technical Details section of this FAQ for more information on this process.

How do I cancel my subscription?

Your subscription is managed entirely by the App Store and follows standard App Store policies. You can cancel your subscription at any time up to 24 hours before your renewal date. You will continue to have full access to Omnipedia, including library updates, until your subscription expires. You can cancel within the Omnipedia app, from the App Store app, from iOS Settings, or at account.apple.com.

Downloads

How do I download a library?

We refer to the different language editions of Wikipedia as “libraries”. Once you’ve subscribed to Omnipedia, you can pick which libraries you would like to download. To download a library, go into the “Libraries” section of the Omnipedia settings and tap “Add Library”. Tap on the language edition you would like to download and then tap the “Download Now” button.

Since downloads can take a long time, it is best to perform the download when you’re on a stable internet connection. If you close the Omnipedia app, the download should continue in the background. However, if you leave the app closed for an extended period or if you make heavy use of other apps, the background download may be interrupted and the installation may not complete. We therefore recommend keeping the app open or checking in on it periodically until the download has completed.

How long does it take to download?

A complete Omnipedia library is between 1 and 12 GB (depending on the language) and can typically be downloaded in less than an hour on most home internet connections. On super-fast fiber connections, the time to download may be as low as five minutes.

Once you’ve downloaded a library, future monthly updates are much smaller and can usually be installed in less than five minutes (depending on the the language, network conditions, and processor speed). Once you start a download or update, the app will display an estimate of the time remaining based on your connection speed.

Can I download multiple libraries?

Yes – your subscription allows you to download as many libraries as you want, so long as you have sufficient storage space.

How often do you publish updates?

We release library updates once per month, typically around the 5th of each month. A small red dot will appear on the Omnipedia settings icon to let you know when an update is available.

Do I have to download every update?

No. You can choose when to perform updates and how often you want to perform them. It’s also possible to skip updates. For example, if you currently have the April snapshot installed, it is possible to update directly to the August snapshot without installing each of the intermediate snapshots for May, June, and July.

I got the message “Insufficient storage capacity to perform update” but I have plenty of space.

During the update process, an entirely new copy of the library is created. Once the update is complete and the new copy of the library has been verified, the original copy of the library is then removed. This is to prevent the original library getting into a corrupted or partially complete state (e.g., due to an abrupt termination of the app or a loss of internet connection).

For example, if you have a 10 GB library installed and you want to update to a new version, you’ll need at least 10 GB of free space (i.e., in addition to the 10 GB already consumed by the library). Once the update process has completed, you’ll get this 10 GB back.

If you’re not able to free up sufficient space on your device to perform an update, one option is to delete the library and reinstall it. This will allow you to get the latest version, but it will take a lot longer to download. If you choose to do this, you can select the “Delete Library Archive” option, which removes the underlying archive files without deleting your bookmarks and history.

Article Content

Which languages is Omnipedia available in?

Currently, Omnipedia supports 11 editions of Wikipedia: Arabic, Chinese, Dutch, English, French, German, Italian, Japanese, Portuguese, Russian, and Spanish.

Can I use multiple languages?

Yes – your subscription allows you to download multiple libraries (language editions). If you have multiple libraries installed, you can switch between them using the language menu in the toolbar.

Do you make any changes to the original Wikipedia articles?

Our goal is to give you offline access to the Wikipedia articles that you love, while keeping the on-device storage footprint as small as possible. This means making some trade-offs. While we do not make editorial changes, we do remove some parts of articles in order to achieve smaller file sizes and faster downloads. In particular, images are not included because the size of the archive would be too large for most devices and it would take a very long time to download. We also remove some end-matter and metadata components, such as references and editorial notes, since these are typically not very useful in an offline context.

Retained article components

Removed article components

But remember: The original Wikipedia article is always just a tap away if you ever need it (and have an internet connection).

Can I share articles with others?

We make a distinction between article content (Markdown-formatted articles derived from Wikipedia) and Omnipedia libraries (Codex container archives used to distribute that content).

Article content is licensed under the Creative Commons Attribution-ShareAlike 4.0 International License (CC BY-SA 4.0). You are free to share, adapt, and reuse this content, provided you follow the terms of that license. In particular, you must provide appropriate attribution to Wikipedia contributors and Omnipedia, and you must license any derivative works under the same terms.

Omnipedia libraries are under copyright and may not be redistributed in their packaged form. However, as a licensee of CC BY-SA content, you are permitted to extract and reuse the articles contained within these libraries, subject to the terms of that license (as described above).

The Omnipedia app allows you to export individual articles in Markdown or HTML format. For technical users who would like to extract many or all articles from a Codex archive, we provide an open-source Python implementation of the Codex decoder to help you do that.

You can find more information in our Terms of Service.

How do I report erroneous information or problematic content?

If the issue is with the original Wikipedia article, it is best to report the problem directly to Wikipedia. In many cases you can edit the Wikipedia page yourself, or you can discuss the issue through Wikipedia’s “Talk” pages. Once the issue is fixed in Wikipedia, it will be mirrored in Omnipedia in the next monthly update cycle.

If you discover an issue that is specific to Omnipedia, such as missing or corrupted text, please use the “Report a Problem” option from the article in question, and then give a brief description of the issue. We do not make changes to Wikipedia articles, but we can fix things if they are not displaying correctly in Omnipedia. Please do remember, however, that certain parts of the original Wikipedia article, such as images and references, are removed from the Omnipedia version by design (as described above).

App Features

How are the articles chosen on the Explore screen?

The articles recommended on the Explore screen are chosen pseudorandomly, with greater weight given to articles that appear more interesting based on various heuristics. The app also draws on your reading history to produce more personalized recommendations. The recommender algorithm uses on-device machine learning models to classify and rank articles, and you can customize the behavior of the algorithm from the settings (for example, you can turn off particular topics that you’re not interested in).

How does search work in Omnipedia?

Because Omnipedia libraries are stored on your device in a compressed state, it is not feasible to perform a complete search of all article content in real time. Instead, when you perform a search in Omnipedia, you get a list of articles whose titles begin with your search query.

For example, if you search for “united”, you will find articles like “United Airlines”, “United Nations”, and “United States”, but you will not find articles like “Workers United”.

However, the search index does include all of Wikipedia’s redirection pointers. For example, “USA” redirects to “United States” and “US President” redirects to “President of the United States”. So, even if you don’t know the exact title, you may be pointed to the right article anyway.

If your search doesn’t bring up any results, try to imagine what the Wikipedia title might be and rephrase accordingly. Once you’ve opened an article, there is a separate in-page search feature that allows you to search for snippets of text within the article.

How does article assistance work?

The article assistance feature helps you quickly answer specific questions about an article. Once you’ve opened an article, tap the chat button and type in your question. Omnipedia will try to provide a helpful answer grounded in the article content. You can even ask follow-up questions, just like using an online chat assistant.

Under the hood, Omnipedia uses an on-device large language model (LLM) to interpret the article and generate responses to your questions. This means the feature is totally private and works even when you don’t have an internet connection! However, because the on-device model is relatively small, its answers may be less comprehensive than those provided by cloud-based services like ChatGPT or Google Gemini.

As with any LLM, the model can produce incorrect answers, so it’s a good idea to verify critical details with other sources. The app will usually point you to specific sections of the article where you can read more.

The article assistance feature requires iOS 26 and a device compatible with Apple Intelligence. If you haven’t already, you may first need to enable Apple Intelligence in your device settings.

Technical Details

Which platforms is Omnipedia available on?

Omnipedia is currently available on iPhone and iPad, and we are planning to add support for Mac in a future update. All platforms are covered by a single Omnipedia subscription.

Does Omnipedia sync between devices?

Omnipedia does not currently sync between devices, although we are looking into ways that we can support this in the future. You can use Omnipedia on multiple devices linked to your App Store account, but each copy of Omnipedia will function independently.

What file format does Omnipedia use to store articles?

Omnipedia libraries are stored in an archive format called Codex that was developed by the Omnipedia team for the express purpose of distributing large-scale encyclopedic content. The Codex format uses block compression to achieve a good balance between compression ratio and random access speed, and archives are broken up into many “shards” to allow for fault-tolerant, resumable downloads. The Codex format permits title searches and individual article access without decompressing the entire library on device, and it supports incremental updates, so that articles can be updated without being re-downloaded in their entirety. The articles themselves are stored in Markdown, a modern, lightweight, plaintext markup format that is human- and machine-readable.

For technical users who would like to extract articles from a Codex archive or explore the data in other ways, we provide an open-source Python implementation of the Codex decoder, which you can run on a Mac or PC.

Are Omnipedia libraries backed up to iCloud?

Omnipedia libraries are not backed up to iCloud because doing so would consume a lot of your iCloud storage space. Indeed, if you’re on the free iCloud tier (5 GB), you wouldn’t have sufficient space to perform a backup anyway. However, your bookmarks and reading history are backed up to iCloud, and you can re-download Omnipedia libraries if necessary (for example, if you upgrade to a new device).

How do I make a personal backup of the library?

By connecting your device to a Mac or PC, you will be able to see the underlying Codex files associated with the Omnipedia library. These files will have names like “enwiki_20260120_complete.000.codex” numbered from 000 to 255. You can transfer these files to your computer by following the steps described in this Apple support article for Mac or this Apple support article for Windows.

To restore from a backup, you can simply copy the same files back to your device, being sure to copy them to the Omnipedia app. Note that the Omnipedia app will only recognize Codex files for libraries you installed during your subscription period. If you delete the library from the Omnipedia app, or if you delete the app itself, there will no longer be a record of which libraries you had installed and the app will not recognize the Codex files.