Frequently asked questions

A question-and-answer page about a browser-local RAG tool: what stays inside the tab, what the one outbound request carries, which files work, how large the models are, and where the approach stops being a good fit.

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SecureRAG answers questions about your own documents without sending them anywhere: parsing, chunking, embedding and retrieval all run in the browser tab, the models are downloaded once into your own Cache Storage, and there is no account, no server-side index and no upload step to audit. The answers below state the limits of that arrangement as plainly as its benefits.

Two checks you can run in a minute

Privacy claims are worth only what you can test. Both of these take under a minute in a desktop browser, and neither needs any special access.

  1. Press F12 to open DevTools, switch to the Network tab, and clear the list. Filter for Fetch/XHR, then drop a file into the workspace. No request carries the file: only GET requests for model weight files appear, and the model is fetched once per model, not once per document.
  2. Switch the Network tab to offline. Ask a question about the document you just imported: the answer, with its cited passages, still comes back, which is only possible if nothing needed the network.
  3. In the Application tab, expand IndexedDB, open the securerag database and its library store: the docs key holds one metadata record per document, and each document also has an index key holding its chunk text together with the Float32Array vectors. Clear site data and both disappear.

Limits and formats at a glance

Table 1 — formats, ceilings and settings, as shipped in v0.1
ItemValue or answer
Supported formatsPDF with a text layer, DOCX, TXT, Markdown, CSV, HTML, JSON
Rejected filesEncrypted PDF, scanned PDF without a text layer, legacy .doc, any single file over 25 MB
File size ceiling25 MB per file
Files per knowledge base40 on desktop, 10 on phones
Total size per knowledge base200 MB
Chunks per knowledge base20,000
Default embedder, Chinesebge-small-zh-v1.5, about 25 MB
Default embedder, Englishall-MiniLM-L6-v2, about 23 MB
Mixed Chinese and Englishmultilingual-e5-small, about 120 MB
Optional generatorQwen2.5 0.5B to 1.5B, 4-bit quantised, 400 MB to 1.0 GB, needs a confirmation click
Generation speedAbout 3-8 tokens per second on CPU/WASM, faster where WebGPU is available
RetrievalVector search plus BM25, fused with RRF (k=60), MMR at lambda 0.7, top 6 passages
Works offlineYes, once the model weights are cached

Questions and answers

How can I verify that nothing is uploaded?

Open DevTools with F12, go to the Network tab, clear the list and filter by Fetch/XHR, then drop a file into the workspace. No request carries the file: parsing, chunking and embedding happen in the same tab that displays the result. The only outbound requests are GET calls for model weight files, which carry a file name and nothing else. Switch DevTools to offline mode after a model is cached and the tool keeps working.

Where are my documents and vectors stored?

In your own browser profile. Text chunks and their vectors sit in IndexedDB for this site, the model weights in Cache Storage, and your settings in local storage. Nothing is written to a server, so there is no remote copy for us to hold, leak or hand over. Clearing site data for this site removes all three at once.

Which file types can I import?

PDF with a text layer, DOCX, TXT, Markdown, CSV, HTML and JSON. The importer sniffs the magic bytes first, so a file renamed from .doc to .docx is rejected rather than half-parsed. PDF page numbers and DOCX heading levels survive parsing, which is why a citation can point at a page or a section instead of a character offset.

Which files are rejected outright?

Encrypted PDFs, scanned PDFs with no text layer, legacy .doc files, and any single file above 25 MB. Each rejection is reported by its own name — PDF_ENCRYPTED, PDF_NO_TEXT_LAYER, LEGACY_DOC, FILE_TOO_LARGE, UNSUPPORTED_FORMAT — instead of a generic failure, so you know whether to remove a password, run OCR, convert the format, or split the file. A PDF that yields fewer than 40 characters of text is treated as a scan rather than as an empty document.

Can I use it on a phone?

Yes, with a smaller allowance: the per-knowledge-base limit drops from 40 files to 10 on mobile. Embedding runs several times slower on a phone CPU than on a laptop, and the optional generator is usually too slow to be pleasant there. On a phone, extraction mode with citations is the practical choice.

How large are the models, and when are they downloaded?

The default embedder is bge-small-zh-v1.5 at about 25 MB for Chinese or all-MiniLM-L6-v2 at about 23 MB for English; multilingual-e5-small, for mixed Chinese and English text, is about 120 MB. The optional generator, Qwen2.5 0.5B to 1.5B in 4-bit quantisation, costs 400 MB to 1.0 GB and downloads only after you press a button that names the size.

Why is it slower than a hosted assistant?

Nothing was precomputed for you. Chunks are embedded on your hardware, and with the local generator enabled every token is produced there too, at roughly 3-8 tokens per second on CPU/WASM. A hosted service amortises one GPU across many users; here you spend your own CPU time and get the privacy in return. The second question about the same document is faster, because the index and the model are already local.

How is a free site funded?

By Google AdSense, on every page, up to six labelled slots (three in-page banners, two side rails, one collapsible anchor). Personalized ads load personalized only after you agree. Decline and the tool behaves identically: outside the EEA, UK and Switzerland you still get non-personalized ads, and inside them no ad script loads at all. There is no paid tier, no account and no data product.

Do you train models on my documents?

No. The models here run inference only: they compute vectors and answers, never gradients, and no feedback path writes your text back into a model. We could not train on your content even if we wanted to, because no copy of it reaches us at any point.

Can I use it at work or commercially?

Yes. The terms place no fee and no licence restriction on the tool: it is free to use, including for work and commercial purposes, and your documents, questions and answers remain yours. Two things sit outside that answer. The downloaded models carry their own licences, listed per model on the models page and governed by the upstream model page rather than by us. And no accuracy is warranted, so a decision that has to satisfy a regulator, an auditor or a client still needs a human to check the cited passage against the source document.

How many documents fit in one knowledge base?

Up to 40 files, 200 MB in total and 20,000 chunks per knowledge base, with a 25 MB ceiling on any single file; on phones the file cap is 10. When a limit is reached the importer says which one it was. Removing the largest file you no longer need clears the block in most cases.

Does it work offline?

After the model weights are cached, yes. Put the browser into offline mode, close the tab, reopen the site and ask a question: parsing, retrieval and extraction all run locally. The model download is the only step that needs a network, and it happens once per model, not once per session.

What can I export, and how?

A session exports from the chat panel as Markdown, JSON or plain text, and the export carries the model name, the strictness setting and every citation, which is the most reliable way to keep an answer next to its sources. Answers also copy to the clipboard, and browser printing produces a PDF of any page. No part of the export touches a server, because there is no server to run the job.

The answer looks wrong. What should I do?

Read the citations before doubting the tool. If the passage that contains the answer is not among them, the problem is retrieval rather than reading: raise strictness, ask a narrower question, or re-import the document when repeated headers and footers are crowding out the body text. If the right passage is cited and the answer still misreads it, switch strictness to “Documents only” and read the passage yourself.

Can it read tables?

Only as text. In a PDF a table is flattened into lines in reading order, so a wide table with merged cells loses its column alignment; a CSV keeps each row intact. Where the columns carry the meaning, converting the table to CSV before importing gives noticeably better answers.

What about scanned PDFs and images?

Scanned PDFs with no text layer are not supported: the parser finds no characters and returns nothing, and the importer says so rather than pretending the file was indexed. No OCR model is bundled, because one would add hundreds of megabytes to the download for a case a browser handles poorly. Run OCR in another tool first, then import the text-layer PDF or the exported TXT.

Can I open a password-protected PDF?

No. Encrypted PDFs are rejected before parsing and no password field appears, because the app has no decryption path. Remove the password in a PDF reader and import the unprotected copy; the original file on your disk is untouched either way.

How does this compare with an assistant that accepts uploads?

A hosted assistant usually answers better: larger models, faster replies, and abilities this tool does not attempt, such as reading charts. The trade is what happens to your file. If the documents are public and you want the strongest answers, a hosted assistant wins. If the text is confidential, regulated, or simply not yours to upload, keeping it local is the point.

Can I run it in a controlled corporate environment?

Usually yes, and it is easier to approve than a cloud tool: the site is static files, the single outbound request is a model download, and you can host the model weights on an internal mirror and point the app there instead of at a public host. Two caveats: the machine needs a current browser with WebAssembly support and writable browser storage, and managed devices that lock down site storage will not run it at all.

Which browsers are supported?

Current Chrome and Edge, plus recent Firefox and Safari versions with WebAssembly. WebGPU, used only for the optional generation model, is present in current Chromium browsers; everywhere else the pipeline falls back to CPU/WASM, which is slower. A private window works, but its index is discarded when the window closes.

Do the ads receive my documents or my questions?

Ad slots sit outside the chat workspace, and no document text, chunk or question is handed to the advertising script. What an ad request carries is the page address plus the standard device and browser details any ad request includes. If you would rather have no third-party script at all, decline the consent message — inside the EEA, UK and Switzerland that stops every ad request outright; elsewhere it narrows requests to non-personalized ones.

Can I search several file formats at the same time?

Yes. Add PDFs, Word files, spreadsheets and notes together and they are searched as one collection; each result says which file and which paragraph it came from.

Can I upload many files and search across all of them?

You can add as many as you like. Strictly speaking there is no upload step: the browser opens the files for us straight from your disk, so they never leave your computer.

What is the difference between exact and fuzzy search?

Exact search returns only sentences containing your text as typed - whole words in English, case-insensitive - with no model involved, so it works the moment the page loads, before anything is downloaded. Fuzzy search takes the semantic path and returns sentences that mean something similar, which is what you want when you are hunting a concept rather than a phrase.

Do I need to install anything or create an account?

No. Open the page and use it: no account, no installer, no sign-in. Once the model is cached it keeps working with the network off.

How is this different from pasting a file into an AI chatbot?

Two differences that matter: your file is never sent anywhere, and every answer is assembled from the sentences in your own documents with numbers that jump back to the paragraph, so you verify the source rather than a rewrite.

Will it miss sentences that contain my words?

Exact search walks every sentence of every file and lists all of them in document order, unfiltered, instead of handing you a few “most relevant” hits. Only fuzzy search ranks, and the two are separate buttons.

Does it work in Chinese and English?

Both. Chinese matches as a substring, English as whole words, case-insensitively, and a single file can mix the two.

Is it slow with large files?

The first pass parses and indexes, so the bigger the document the longer that step takes, and the progress bar tells you where it is. Searching an index that already exists takes milliseconds, and the index lives in your browser, so you do not rebuild it next time.

What happens to my files after I close the tab?

The index is kept in your browser’s local storage, so it is still there when you come back. Clearing your browser data removes it along with everything else - that is the “deleting really deletes” part.

If your question is not here

Send it to guweiicy@gmail.com with your browser name and version, the file type you were using and the exact wording of any message you saw. Questions that turn out to expose a real gap are answered and then added to this page, so the next person does not have to ask.

This page carries ad slots too. It sits below the article and outside the chat workspace, and no document text or question is passed to it. The privacy policy, the terms and the security pages carry ad slots at all.