Local PDF assistant
An assistant that reads your document without ever letting it leave your device.
Your files never leave your deviceFrequently asked questions
Does my PDF’s content get sent to a server for the assistant to answer?
No. The language model runs in your browser, on your device’s graphics card, once downloaded. The network witness shown under each answer proves it: 0 bytes sent while the assistant is answering. Only the initial model download, announced before your click, comes from another site (huggingface.co).
Why do I need to download something before I can start?
The language model itself (about 850 MB by default, or 2.2 GB for the "more precise" option) is not bundled with Vellum: it downloads once, on your click, and then stays in your browser’s cache. A "Delete the model from this device" button erases it whenever you want.
What happens if my browser does not support WebGPU?
The panel explains it and offers no loading button: there is no fallback to a server. WebGPU is available in recent versions of Chrome, Edge and Firefox, and in Safari from version 26 onward.
Are the assistant’s summaries and answers 100% reliable?
No, and the interface says so at every step: it is a small model running on your device, capable of a faithful summary but not a legal opinion. Always check important details in the document itself, especially extracted amounts and dates.
How does the assistant handle a document too long for a single request?
The text is split by page into chunks of about 2,400 tokens. A summary spanning more than one chunk is done in two passes — a summary of each chunk, then a summary of those summaries — and the interface says so in one sentence. For a question, the model, on your device, reads only the two most relevant chunks.