Commonplace
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Ask Wikipedia in airplane mode.

A free Android app that answers from Wikipedia stored on your phone. It cites every source and never goes online.1

Download the APK Read the source code

Android 12 or later, a 64-bit ARM phone and 8 GB of RAM. No Google Play Services. Open source under Apache-2.0.

2:14
Commonplace
Ready · CPU
What causes the northern lights?
Answered from 5 sources · 5.0 s
Northern LightsEnglish Wikivoyage · CC BY-SA 4.0

… gas molecules in the earth's upper atmosphere, energising them and creating a spectacular multi-coloured light show. Charged particles are affected by magnetic fields, so the Lights occur mainly at far northern or southern latitudes near the Earth's magnetic poles. …

subclass of
astrophysical process, optical phenomenon, electrometeor
Wikidata

The northern lights are caused by charged particles from the Sun that interact with Earth's magnetic field.1,2,3,5 These particles become trapped in the magnetosphere and travel toward the Earth's magnetic poles, where they collide with atoms in the upper atmosphere, producing the visible glow.1,3

Ask your library…
Real answers from the app, recorded on a Pixel 10 in airplane mode. The replay runs faster than the phone.

Every claim points to a passage.

The best passage shows up first, with the key sentence highlighted. Then a small AI model writes the answer and numbers each claim.

Tap a number to open the passage, with its credit and its license. When an answer has a number that the evidence does not have, the app underlines that sentence, so you know what to check.2 Comparisons put facts from Wikidata side by side.

This page works the same way. Tap a red number to see where a claim comes from.

  1. 2It underlines a sentence when the evidence does not have one of its numbers. README, Design choices
An answer that compares Mars and Venus, with a Wikidata table of area, highest point and lowest point
Compare two things. Wikidata facts sit side by side.
The source reader: the passage, its credit, its license and its web address
Open any source to check it.

Nothing leaves the phone.

You do not have to trust a setting. Commonplace does not ask Android for the internet permission, so Android blocks every connection.1

Your questions, your library and the AI model stay on the phone. You download the library once with your browser, and the app imports it from the Downloads folder. A release cannot ship with the permission: the release script stops if it appears.3

To check it yourself, turn on airplane mode. Or open Settings, then Apps, then Commonplace, then Permissions.

6<uses-permission
  android:name="android.permission.INTERNET"
  tools:node="remove" />
7<uses-permission
  android:name="android.permission.ACCESS_NETWORK_STATE"
  tools:node="remove" />
9<uses-permission
  android:name="android.permission.RECORD_AUDIO" />
The app's manifest removes the two network permissions. The microphone permission is for voice input, which also runs on the phone.
  1. 1INTERNET … tools:node="remove" AndroidManifest.xml, lines 6 and 7
  2. 3INTERNET permission in the release APK scripts/release.sh, lines 48 and 49

The reading happens before you ask.

Once, on a desktop computer

The library is prepared

A computer reads Wikipedia, Wikidata and other open reference works. It splits them into short passages and builds search indexes. You download the result once, over Wi-Fi.

Every day, on your phone

The phone only looks things up

When you ask, the app finds the best passages in about a second. A small AI model then reads only those passages and writes a short answer with citations.

From question to answer

Median times on a Pixel 10, from the moment you tap send.

Gemma 4 E2B on the Tensor chip 0.61 sbest passage 1.9 sfirst word 7.5 sfull answer
Ling-3.0-tiny on the CPU 0.50 sbest passage 7.2 sfirst word
  1. 4Answer card 0.61 s median, first word 1.9 s median, full answer 7.5 s median for Gemma; 0.50 s and 7.2 s for Ling. Ling writes 16 to 17 words per second on a cool phone, so a full answer on the CPU takes longer. README, Results on the Pixel 10

Only the Pixel 10 runs Gemma on its Tensor chip.4 Other phones answer on the CPU with Ling-3.0-tiny, or with MiniCPM5-2B on 8 GB phones.

Your library, up to 50 GB.

Knowledge comes in packs. Each pack is one file, and each one has an on/off switch in the app. The app checks every byte with SHA-256 when it imports a pack.

  • Starter setFor 12 GB phones

    11.3 GB

    English Wikipedia, Wikidata facts and the Ling-3.0-tiny model.

  • Starter set, smallFor 8 GB phones

    8.1 GB

    The same library with the smaller MiniCPM5-2B model.

  • Reference shelfRecommended

    2.0 GB

    13 packs: Wikivoyage, Wiktionary, Wikibooks, Wikiquote, Wikiversity, open textbooks, OpenStax, MedlinePlus, CDC travel health, the CIA World Factbook, ArchWiki, DevDocs and WikEM.

  • Gemma 4 E2BFor the Pixel 10

    3.1 GB

    The fastest model. It runs on the Tensor G5 chip.

  • More packs

    The full English Wikipedia (19.2 GB, in place of the starter's Wikipedia), arXiv abstracts (3.3 GB), Stack Exchange from 51 sites (2.5 GB) and English voice input (0.3 GB).

Full Wikipedia, 19.2 GB AI and voice models, 6.3 GB Wikidata facts, 3.2 GB arXiv and Stack Exchange, 5.8 GB Reference shelf, 2.0 GB

Every pack together uses 36.5 GB, and the Gemma pack adds 3.1 GB on a Pixel 10.5 The app refuses an import that would take the total above 50 GB.

  1. 5All packs together use 36.5 GB, plus the app. Sizes per pack come from the catalog of the packs on Hugging Face.
The Library screen with the storage meter and a switch for each pack
The Library shows what is installed and how much room is left.
An answer from the user's own PDF, limited to that document
Add your own PDF, text or Markdown files. The app indexes them on the phone, and citations show the page.

Half the score of Claude with web search.

On 63 test questions, Commonplace gets 53% of the score of Claude Opus 5.5 with web search.6

Claude answers each question with the web. A second Claude call grades both answers without knowing which is which. It scores correctness, completeness, grounding and usefulness.

The online model still wins almost every single question. Commonplace gets half the points, not half the wins. Travel, rare topics and plain facts are the weakest types. The Reference shelf lifts travel from 41% to 53%.7

  1. 6overall: 0.53 (target ≥ 0.50) Run v22-answer-rules, Starter set, the phone's settings, 2026-10-22. Each type has only 3 to 11 questions, and the judge varies by about ±5 points between runs. docs/EVAL.md
  2. 7The Reference shelf raises travel from 0.41 to 0.53 docs/BENCHMARKS.md, Seeds over time

Download once, then go offline.

  1. Install the app. On the phone, open the latest release and download the APK. Open the file to install it.

  2. See what your phone needs. Open Commonplace. The Get started card names the files for your phone and their sizes.

  3. Download the library. Tap Open Library, then each file under Get more. Your browser saves them in Downloads. Use Wi-Fi: on a slow 2.4 GHz network, the 11.3 GB set took 3 hours.

  4. Import it. Tap Install from Downloads and select the files. The app checks them while it copies them, then offers to delete the downloads.

  5. Ask. Turn on airplane mode if you like. The first question takes longer, because the app loads the model.

You need

  • Android 12 or later on a 64-bit ARM phone
  • 8 GB of RAM: the app uses at most 5.3 GB with Ling, 2.6 GB with MiniCPM5-2B and 2.3 GB with Gemma
  • Free storage of about twice the download for the first import

Tested on a Pixel 10 with GrapheneOS.

Questions to try

  • Compare the Nile and the AmazonWikidata facts side by side, then a written comparison
  • Walking 5 km an hour, how long would it take to walk the length of the Great Wall of China?Code computes the time from Wikidata
  • Do I need to tip in Japan?A travel answer from Wikivoyage, with the Reference shelf
  • Who built the pyramids of Giza? Then: How long did it take to build them?A follow-up keeps the topic

Next, it reads answers aloud.

That and two more plans, in no particular order. Each one ships when it is ready.

  • Read-aloud mode

    The phone reads the answer to you with an on-device voice. No network.

  • Faster on every phone

    A quicker model start and a faster first word on phones that answer on the CPU.

  • Better on older phones

    Smaller models and settings for phones that are a few years old.

About the community token

Members of the community launched a token named Commonplace on Base, through Bankr. Thank you for the support. The token is a community project, not part of the app: you never need it, or a wallet, to use Commonplace. I can't make promises about its price or its future, and nothing here is financial advice.

Bankr sends a share of the token's trading fees to me, and they help fund development. I will never ask you to connect a wallet or send funds, so please ignore anyone who does in my name.

Contract on Base: 0x334dbefdedc6ff68d5a883e5ea27a37a137d5ba3