Enter your data or use the example, then run the tool.
Worked example
Headings/lists/emphasis remain; raw script markup stays text and the remote image is removed without a request.
Method
Marked lexes/parses real GFM in a worker. Raw HTML is escaped, then DOMPurify cleans the generated result. Preview has no scripts, origin access or resources; downloads include restrictive CSP.
Limits
Markdown ≤100,000 characters; token depth ≤40 / 10,000 nodes. Links/images omitted, raw HTML never runs. No plugins/remote includes or exact renderer-compatibility guarantee. Worker limit 2.5 seconds. Original Markdown download stays text.
All work stays in this browser. Each disposable worker is terminated after 2.5 seconds or cancellation. Inputs and processing logs are not sent to analytics.
Sanitized HTML ≤1 million characters / 10,000 elements / depth 50. No links, images or active content are retained.
Your inputs stay on this device. Only optional, consented page visits are measured. Input values, files, filenames and processing logs are not sent to Analytics.
When switching languages, text, settings and selected files are temporarily kept on this device. Transfers are removed after restoring; interrupted transfers are cleaned up on a later visit. Inputs and files are never uploaded.