The latest articles on DEV Community by Yonghye Kwon (@developer0hye). https://dev.to/developer0hye https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F3818688%2Fe4278b92-d1fc-4842-968e-814daa33cb47.png https://dev.to/developer0hye en Yonghye Kwon Wed, 11 Mar 2026 15:52:25 +0000 https://dev.to/developer0hye/browser-only-markdown-to-pdf-tool-supports-math-equations-mermaid-diagrams-and-github-repos-no-4nij https://dev.to/developer0hye/browser-only-markdown-to-pdf-tool-supports-math-equations-mermaid-diagrams-and-github-repos-no-4nij <p><a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fdorkm6tkhfmmcmivexsn.gif" class="article-body-image-wrapper"><img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fdorkm6tkhfmmcmivexsn.gif" alt="example video" width="720" height="468"></a></p> <p>Hey everyone! I've been working on a side project and wanted to share it.</p> <h2> What I built </h2> <p><strong>dontsendfile.com/md2pdf</strong> — A free Markdown to PDF converter where your files never leave your browser. Everything runs client-side via WebAssembly. No uploads, no servers touching your data.</p> <h2> Why I built it </h2> <p>Most online converters require you to upload your files to some random server. I wanted a tool where I could convert sensitive docs (meeting notes, internal specs, personal journals) without trusting a third party.</p> <h2> Key features </h2> <ul> <li> <strong>100% browser-based</strong> — Powered by WebAssembly, nothing is sent to any server</li> <li> <strong>LaTeX math equations</strong> — Inline and block math rendered via MathJax</li> <li> <strong>Mermaid diagrams</strong> — Flowcharts, sequence diagrams, etc. rendered as SVG</li> <li> <strong>GitHub repo support</strong> — Paste a GitHub URL and convert any .md file directly</li> <li> <strong>Local folder support</strong> — Drop a folder with multiple .md files and images</li> <li> <strong>Batch export</strong> — Select multiple files and export them all at once</li> <li> <strong>GitHub-flavored Markdown</strong> — Tables, code blocks, task lists, and more</li> </ul> <h2> The engine behind it: marknest </h2> <p>The core rendering is powered by <strong>marknest</strong> (<a href="https://github.com/developer0hye/marknest" rel="noopener noreferrer">https://github.com/developer0hye/marknest</a>), an open-source Markdown-to-HTML renderer I built in Rust, compiled to WebAssembly. It handles Mermaid diagrams, math equations, and theming — all running in the browser with zero server dependency.</p> <h2> Tech stack </h2> <ul> <li> <strong>marknest</strong> (Rust -&gt; WASM) for Markdown rendering</li> <li> <strong>Next.js</strong> (App Router) for the site</li> <li> <strong>MathJax</strong> &amp; <strong>Mermaid.js</strong> bundled as client-side runtime assets</li> </ul> <h2> Try it </h2> <p><a href="https://dontsendfile.com/md2pdf" rel="noopener noreferrer">https://dontsendfile.com/md2pdf</a></p> <p>Would love your feedback — especially on rendering quality and any Markdown edge cases you run into. Thanks for checking it out!</p> privacy showdev tooling webdev