MicroRAG is a free, open-source AI that answers questions from your own documents, with citations, and never needs the internet. Put your PDFs, notes and scans on an SD card, plug it in, and ask in plain English. Nothing is uploaded. There is no account.
A made-up sample so you can see the shape of an answer. Real answers cite your files.
The real app
The vault as it opens: drop in files, ask a question, and use the tools on the left to see the vault map, find contradictions and check that nothing leaves your computer.
The technical reason
MicroRAG reads a model file of about 2.3 GB every time it starts, then hits the search index on every question. How fast your storage reads decides how fast it feels. That is where a card in a built-in slot wins.
Time to load the 4B model from the same SanDisk Extreme PRO microSD card on the author’s Apple silicon Mac. About 3.5 times faster through the built-in slot. Measured once, so your numbers will differ.
A built-in SD slot has no USB reader or hub in between. In our test, adding a USB reader to the same card made loading 3.5 times slower.
SD cards print performance classes. An A2 card guarantees at least 4,000 random reads per second, and V30 guarantees 30 MB/s sustained writes. Typical USB sticks publish no such floor.
Loading a model is large reads. Searching the index is many small random reads. Those random reads are exactly what the A-class rating measures.
Fair to say: we measured one card through a built-in slot against the same card through a USB reader, not a USB stick head to head. A fast USB 3 SSD drive can match or beat a mediocre card, and Macs without an SD slot need a reader. Buy a card marked A2 or V30 and use the built-in slot if you have one.
Why it exists
Contracts, research, medical notes, client work, family records. Some documents should never be uploaded. MicroRAG keeps the documents, the search index and the AI models on one card, and runs everything on the computer you plug it into.
| MicroRAG | Cloud AI chat | |
|---|---|---|
| Where your files go | Stay on your card and your computer | Uploaded to someone else’s servers |
| Works with no internet | Yes, after the one-time install | No |
| Account or subscription | None. Free and MIT licensed | Usually required |
| Shows its sources | Every answer cites passages, checked against the file | Varies |
| Take it with you | Plug the card into another computer | Tied to your login |
| Raw model power | A small local model. Strong on your documents, weaker than the biggest cloud models on open-ended tasks | Largest models available |
What you get
Everything below runs locally. Nothing here needs a server of ours, because we do not have one.
Ask a question and get an answer built only from your files, with numbered citations. Proof view highlights the exact sentence that backs each claim and shows a strong, partial or weak support badge, plus the page number for PDFs.
Do not take our word for it. A live view lists every connection the app opens. The honest answer should be none.
Scans your vault for passages that disagree, like two contracts with different dates, and shows both sides side by side.
See your whole library as a living map of how documents relate. Spot clusters, gaps and orphans at a glance.
Open your vault from a phone on the same Wi-Fi with a 6-digit PIN. Snap a photo of a page and ask about it. The photo is read on the computer and not kept.
Turn it on and MicroRAG refuses to run while any network is up. Turning it off takes a deliberate step in the terminal.
Drop files onto the app or write a note. Everything is stored as a plain file in your vault folder, so you can back it up or edit it with any tool.
Point it at a folder and get a one-page briefing of what is in there, with sources.
Lock the vault with a passphrase so a lost card is just a lost card.
Photos, screenshots and scanned PDFs are read with on-device OCR. Apple Vision on a Mac.
The proof moment
Flip the switch. A private AI should not care whether you are online, and this one does not.
Illustration of the idea. In the real app, the Zero-Network Proof view checks this on your own machine, and it says plainly what it can and cannot see.
Quick start
You need internet once, to download the models. After that you never do.
Get MicroRAG from GitHub and put it on an SD card. About 5 GB with the models, plus room for your files.
It downloads the runtime and the models onto the card. If a download drops, run it again and it resumes.
Open the start file, wait for ONLINE, drop in your documents and ask.
MicroRAG$ cd /Volumes/MicroRAG-SD && sh install.shWho it is for
Search every client file at once without sending any of it to a cloud.
Ask across contracts and spot conflicting terms, with the page cited.
Query your notes and papers and get answers that point to the source.
Boats, cabins, flights, field sites, or just a careful household.
Straight talk
Questions
MicroRAG is a free, open-source AI knowledge vault. You put your documents on an SD card, plug it into a computer, and ask questions in plain English. It answers from your own files and cites the passages it used. The documents, the search index and the AI models all stay on the card, and everything runs on your computer.
Yes. You need internet once, to download the runtime and models during install. After that it runs with no connection. The Zero-Network Proof view lists the connections the app makes, and Air-gap mode can refuse to run while any network is up.
Speed. MicroRAG loads a model of about 2.3 GB at every start and searches its index on every question, so storage read speed matters most. On the author’s Mac, the same card loaded the 4B model in 31 seconds through the built-in SD slot and 1 minute 48 seconds through a USB card reader. SD cards also print performance classes, such as A2 for random reads, that typical USB sticks do not publish. We did not test a USB stick head to head, and a fast USB 3 SSD drive can match or beat a mediocre card.
No. There is no account, no cloud and no telemetry. Your files, the search index and the models stay on the card, and questions are answered on your own computer.
An SD card with roughly 5 GB free for the app and models, plus room for your files, and a computer. It was built and tested on a Mac. The Windows and Linux launchers are included but untested. 8 GB of RAM works with the small model, and 16 GB or more is comfortable with the larger one.
Text and Markdown files, CSV, JSON and HTML, Word (.docx) and PDF files. Photos, screenshots and scanned PDFs are read with on-device OCR, which uses Apple Vision on a Mac. OCR quality depends on the scan.
Cloud AI chat needs your files uploaded to a server and usually an account. MicroRAG runs locally, needs neither, and shows the source passage for every answer. The trade-off is that it uses a small local model, which is weaker than the largest cloud models on open-ended tasks.
Yes. Any AI can be wrong. MicroRAG cites the passages it used and shows a strong, partial or weak support badge for each answer, so you can check the source before relying on it.
Yes. It is free and released under the MIT license, so you can use, change and share it.
Yes. Phone mode opens your vault on a phone connected to the same Wi-Fi, protected by a 6-digit PIN. Camera Ask lets you photograph a page and ask about it. Phone mode uses plain HTTP on your local network, so use it only on a network you trust.
MicroRAG is developed by William Mapp and released under the MIT license.
Free, open source, and private by design.