Any document to clean, AI-ready Markdown.
PDF, Word, Excel, PowerPoint and 15+ formats — rebuilt as real Markdown with the tokens counted for your model. All in your browser. Nothing is uploaded.
From a flat document to structure your model can use
Other tools dump the text and leave. MarkPrep reads the page's own layout to rebuild headings, lists and tables — and when it can't (a scan), it says so.
Markdown is not the finish line. Your model is.
Every other converter in this category is marketed “for AI.” Not one tells you how many tokens you're holding. MarkPrep counts as it converts — pick your model and the number turns green or red.
A live count, per model, updating as pages process.
Red means it overflows. You immediately see how it breaks up.
Visible boundaries with heading paths, exportable as JSONL.
Convert anything to Markdown
What Markdown alone doesn't give you
It counts before you paste
Live token totals for GPT, Claude and Gemini, updating as each page converts, with a clear verdict against your model's context window. You stop pasting into an LLM and hoping.
Chunks you can actually see
Heading-aware boundaries in the preview, adjustable size and overlap, heading path and page number in every chunk, one-click JSONL export. Retrieval returns whole sections, not fragments.
Nothing leaves your machine
PDF parsing, OCR, table extraction — all compiled to WebAssembly, all in your tab. Convert files you're contractually forbidden from uploading, on a locked-down laptop, without a ticket.
The clean-up nobody else bothers with
Repeated headers, footers, page numbers and hyphenated line-breaks stripped automatically. Your embeddings stop absorbing page furniture.
We show you what we got wrong
Every table with a mismatched column count and every low-confidence scan is flagged, with the issue called out. You catch the broken row before your RAG pipeline does.
Your assistant can use it directly
Run our MCP server locally and Claude Code converts documents itself, on your machine. The conversion step disappears from your workflow.
£19 once. Yours for life.
Every conversion, format, token count and chunk plan — free, forever, in your browser. Pro is a one-time £19 for the workflow around it: the local MCP server, watch folders, saved profiles and sync. No subscription.
Frequently asked questions
Why is this cheaper than everything else?+
Because conversions run on your computer instead of our servers, our fixed costs are about a dollar a month. We're not undercutting with venture money — we just have almost nothing to cover.
Is PDF to Markdown always perfect?+
No. A PDF is a layout format, not clean content. Digital, text-based PDFs convert well; scanned or image-heavy ones are harder — MarkPrep flags when the result looks unreliable rather than pretending it's clean. For anything important, review the Markdown before sharing it with people or AI tools.
If it runs in my browser, is the quality worse?+
On Word, Excel, PowerPoint, HTML, CSV and digital PDFs, no — we run the same open-source parsers locally that hosted tools run remotely. For DOCX we use mammoth.js, the original implementation the Python version was ported from. On difficult scans a GPU tool beats us, and we tell you when a scan looks rough.
Can I use the Markdown for AI skills or agent instructions?+
Yes. Converted Markdown is a strong starting point for AI skill files, agent knowledge, prompt references, runbooks and internal docs — and the token count tells you if it fits your model's context. Review and edit the output before using it in production.
Are the token counts accurate?+
Exact for OpenAI models, which publish their tokenizer. Approximate for Claude and Gemini, which don't — we label those clearly rather than pretending otherwise.
What about large files?+
The limit is your browser's memory, not our policy. A 500-page PDF converts fine on a modern laptop. On a phone, expect slower results above 50 pages.
Do you see my files?+
No. There is no upload endpoint. Two exceptions are labelled every time: fetching a public URL, and bring-your-own-key OCR, which goes from your browser to your own provider using your own key.
Can I use this at work?+
That's who it's for. Nothing leaves the device, so most acceptable-use policies are satisfied without an exception request.
Why pay if conversion is free?+
You shouldn't, unless you want the local MCP server, watch folders, saved profiles or encrypted sync. Most people never need to.
Does it work offline?+
Yes. Install it as a PWA and it keeps converting with the Wi-Fi off — on a plane or an air-gapped machine.
Which formats are supported?+
PDF (digital and scanned), Word, Excel, PowerPoint, HTML, CSV/TSV, JSON, XML, EPUB, Jupyter notebooks, images, plain text, and public URLs.
Do I need an account?+
No. Conversion needs no account. You only sign up for Pro.