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60+ free developer tools that run entirely in your browser — JSON formatter, JWT decoder, Base64, diff checker, regex tester, hash generator and more. No upload, no sign-up, completely private.

JSON & Data

  • JSON Formatter
  • JSON Minifier
  • JSON Validator
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Encode & Decode

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Text Tools

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Generators

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  • NanoID Generator

Popular Guides

  • How to Format and Pretty-Print JSON (Without Breaking It)
  • How to Minify JSON and Shrink Your API Payloads
  • How to Validate JSON and Pinpoint the Exact Syntax Error
  • How to Convert JSON to CSV for Excel and Google Sheets
  • How to Convert CSV to JSON (With Proper Header Detection)
  • All guides →

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© 2026 filemarkr. Designed & developed by Naved Naik.  All processing happens locally in your browser.

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Markdown to HTML

Render Markdown to clean, sanitized HTML with a live preview.

100% private Instant, in-browser Read the guide
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Markdown to HTML Converter

Markdown is the fastest way to write, but browsers, CMS fields, and email templates need HTML. This Markdown to HTML converter turns your Markdown into clean, sanitized HTML with a live preview, so you can see the rendered result and copy production-ready markup for docs, blog posts, and static sites.

How it works

The rendering happens locally in your browser. As you type or paste Markdown, the tool converts headings, lists, links, code blocks, and emphasis into HTML on your machine and sanitizes the output to strip unsafe markup. There's no server involved, so the preview updates instantly and keeps working offline once the page has loaded.

Common use cases

  • Convert a README into HTML for a project website.
  • Paste formatted content into a CMS that expects HTML.
  • Turn notes into an email or newsletter body.
  • Preview exactly how your Markdown will render.

Going the other direction? Use HTML to Markdown to import existing pages. Write and preview longer pieces in the Markdown Editor & Preview, or build tables to include with CSV to Markdown Table.

Private by design

Your Markdown never leaves the browser — no upload, no sign-up, no tracking. The converter is free and runs on every modern browser, including mobile, so your drafts and content stay private to you.

Frequently asked questions

Yes. The converter strips unsafe markup so the HTML it produces is clean and safe to embed.

Related tools

Number Base Converter

Convert numbers between binary, octal, decimal and hexadecimal.

Color Converter

Convert colors between HEX, RGB, HSL and HSV with a live preview.

CSV to Markdown Table

Paste CSV and get a GitHub-flavored Markdown table you can drop into any README.

HTML to Markdown

Convert HTML into tidy Markdown for docs, notes and issues.