Convert anything to Markdown — save AI tokens
HTML, PDF, Word, Excel, CSV, JSON, EPUB → clean Markdown for ChatGPT, Claude, Gemini. Live token counter, per-model cost estimate. Free, no signup.
7 converters
Paste HTML from a webpage, extract clean Markdown. Auto-strips scripts, styles, ads.
Convert Microsoft Word .docx to Markdown. Preserves headings, lists, bold, italic, links.
Convert .xlsx spreadsheets to multiple Markdown tables — one per sheet.
Turn CSV/TSV into clean GitHub-flavoured Markdown tables. Auto-detects delimiter.
Convert JSON objects/arrays to nested headings + lists or key-value tables.
Extract each EPUB chapter to Markdown. Ideal for feeding books into AI.
Extract text from PDF to Markdown. Free tier uses PDF.js (text-only).
Minh Nguyen
Founder · Solo Developer · Phần Mềm Tổng Hợp
I'm Minh Nguyen, an independent developer based in Hà Nội. I graduated from Hanoi University of Science & Technology (HUST) with a CS degree in 2018, took 2nd place at the FPT Software Innovation Hackathon 2017, and finished top 30 at the ACM ICPC Asia Regional 2016 (Northern qualifier).
Since 2018 I've shipped 8 free SaaS tools for Vietnamese users — KiTuDacBiet, ImgTools, OneGen, PDF Toolkit, SEOTool, OneAudio, OneSVG, and MarkdownKit. Shared philosophy: privacy by design (browser-side wherever possible), genuinely free, Vietnamese-first.
MarkdownKit was born from a daily annoyance: I feed PDFs/DOCX/HTML into ChatGPT and Claude every day, and miscounting tokens was costing me real money. This tool counts tokens exactly for GPT-4o, estimates them for Claude/Gemini, and opens results straight in your AI chat — no more manual copy-paste.
Why MarkdownKit?
Live exact token count for GPT-4o, estimates for Claude/Gemini, plus USD cost per feed. Save 60-80% vs feeding raw files.
'Open in ChatGPT/Claude/Gemini' buttons — auto-copies Markdown to clipboard and opens the chat in a new tab. Skip the manual paste.
HTML/JSON/CSV/DOCX/XLSX/EPUB run entirely locally. Files never leave your machine — privacy like a desktop app.
Vietnamese and English UI from day one — not a machine translation. Built for AI users worldwide.
How to use
- 1Pick a converter
Click one of the 7 tools (HTML, Word, Excel, CSV, JSON, EPUB, PDF) below.
- 2Upload or paste
Drag & drop a file, or paste content directly into the input box.
- 3View the output
Markdown appears immediately. Toggle between raw text and rendered preview.
- 4Copy or open in AI
Click 'Open in ChatGPT' to auto-copy + open the chat. Or download as .md.
Frequently asked questions
Is MarkdownKit free?
Yes — 100% free for all 7 client-side tools (HTML, DOCX, XLSX, CSV, JSON, EPUB, PDF basic). No usage limits, no watermark, no signup.
Why use Markdown instead of pasting files into ChatGPT?
Markdown is 60-80% smaller in tokens than HTML/PDF/DOCX raw. Same content, fewer tokens = more room in the context window + cheaper API calls. Critical for heavy AI users.
Is the token counter accurate?
100% accurate for GPT-4o and GPT-4 (uses OpenAI's official tokenizer). For Claude and Gemini it's an estimate (~5% margin) since those vendors don't publish official tokenizers.
Are my files uploaded?
No — for the 6 client-side tools (HTML/DOCX/XLSX/CSV/JSON/EPUB) everything runs in your browser via JavaScript. PDF also uses PDF.js client-side. Verify in DevTools → Network.
Does PDF preserve math equations and tables?
Free tier uses PDF.js — text only. Tables and math may lose layout. For high-quality extraction (preserving tables, math, footnotes), use Marker or Datalab API — coming as a paid tier.
Can I use it commercially?
Absolutely. Markdown you generate is yours — no attribution, no limits.