Markdown Link Rewriter - Online Relativize or Absolutify URLs

Relativization converts absolute URLs (like https://example.com/blog/post/) into relative paths (like ../post/ or post/) based on a reference base URL. This makes your Markdown documents portable across domains and environments — links work whether the content is served from a local dev server, staging, or production.

Absolutification is essential when you need self-contained documents — for email newsletters, RSS feeds, exported PDFs, or sharing Markdown files externally. Relative links like ../images/photo.jpg break when the document is viewed outside its original directory structure. Converting them to full absolute URLs ensures links remain functional everywhere.

Image links in Markdown (![alt](url)) are processed identically to regular inline links. Both relativization and absolutification apply to image URLs, ensuring your visual assets remain correctly referenced after conversion. Reference-style image definitions are also handled.

The tool handles four common link types: inline links [text](url), image links ![alt](url), reference-style definitions [ref]: url, and autolinks <url>. Anchor-only links (like #section), mailto:, tel:, and javascript: URLs are preserved as-is to avoid breaking functionality.

Absolute URLs pointing to different domains (e.g., https://github.com/... when your base URL is https://example.com/) are intentionally left unchanged. Converting cross-domain URLs to relative paths would create broken links. Only same-domain URLs matching the base URL prefix are relativized.

For relativization, set the base URL to the canonical location of your Markdown document (e.g., https://yoursite.com/blog/post-slug/). All same-domain absolute links beneath this path will be converted to relative. For absolutification, the base URL acts as the resolver — relative paths like ./image.png are resolved against this base to produce full absolute URLs.

Yes. Protocol-relative URLs (starting with //) are treated as absolute URLs since they specify a full host. During absolutification, they inherit the protocol from the base URL. During relativization, they are left unchanged unless they share the same host as the base URL.

Absolutely. The conversion uses efficient regex-based matching and operates in O(n) time complexity relative to input length. Files with tens of thousands of links can be processed in milliseconds. The auto-convert feature uses debouncing (300ms delay) to avoid unnecessary recalculations while typing.