Free developer tools
Small, fast, free tools for everyday building. The hosting tools put a file online and ask for a free host0 account when you publish; everything else runs in your browser. The exception: tools that load a live page by URL fetch it through our server, which passes it back without storing it. Built and hosted by host0, the cloud for small software.
Hosting tools
Put a file online: drop a PDF or an HTML page and get a link you can send to anyone, or keep private to the people you invite. Needs a free host0 account.
Markdown tools
Convert Markdown to and from PDF, Word, HTML, and tables — or write it in a live editor. Everything runs in your browser.
Markdown to PDF
Turn Markdown into a clean, styled PDF in your browser
PDF to Markdown
Extract clean, structured Markdown from any text PDF
Markdown to HTML
Convert Markdown to clean HTML, or a full styled page
HTML to Markdown
Turn HTML or pasted rich text into clean Markdown
Markdown to Word
Convert Markdown to a real, editable .docx file
Word to Markdown
Convert .docx Word documents to clean Markdown
Online Markdown editor
Write Markdown with live preview, autosave, and export
CSV to Markdown table
Convert CSV to a Markdown table and back
Excel to Markdown table
Turn spreadsheet cells or .xlsx files into Markdown tables
JSON to Markdown
Convert JSON to Markdown tables and lists, and back
Slack Markdown converter
Convert Markdown to Slack's mrkdwn and preview it
AI coding tools
Generate CLAUDE.md files, slash commands, and hooks for Claude Code — correct syntax, ready to drop into your repo.
Web & SEO tools
Check tags and sitemaps, generate embeds, forms, slugs, and GUIDs, and wrangle HTML, XML, and JSON.
HTML stripper
Strip all tags from HTML and get clean plain text
Iframe generator
Build iframe embed code for any URL with a live preview
Embed code generator
Responsive embed code for videos, maps, and any URL
Meta tag checker
Audit a page's title, meta, canonical, OG and heading tags
H1 checker
Find missing, duplicate, or empty H1 tags on any page
XML viewer
Pretty-print, validate, and explore XML in a tree view
JSON diff checker
Compare two JSON documents and see every changed value
Sitemap validator
Validate XML sitemaps against the sitemaps.org spec
HTML form generator
Compose a form field by field and copy clean HTML
Hreflang generator
Generate hreflang link tags for multilingual pages
Slug generator
Turn titles into clean, SEO-friendly URL slugs
HTML to PDF converter
Render HTML and save it as a PDF, right in the browser
IPYNB to HTML converter
Convert Jupyter notebooks to standalone HTML pages
HTML encoder
Escape and unescape HTML entities both directions
GUID generator
Generate cryptographically random GUIDs / UUID v4s
These tools are small software — yours can be too
Every tool on this page is the kind of thing an agent builds in one conversation. host0 owns the step after: say "Deploy to host0" and it's live at a shareable URL, with a database if it needs one.