# Svelte Markdown vs svelte-exmarkdown Two Runtime Renderers, Different Engines ## Overview Compare svelte-exmarkdown and @humanspeak/svelte-markdown: unified-based runtime rendering versus marked-powered Svelte 5 renderers and streaming support. - **Svelte Markdown site:** https://markdown.svelte.page - **Svelte Markdown npm:** https://www.npmjs.com/package/%40humanspeak%2Fsvelte-markdown - **Svelte Markdown slug:** svelte-markdown - **Category:** Runtime Renderer - **Approach:** unified/remark/rehype pipeline - **GitHub:** https://github.com/ssssota/svelte-exmarkdown - **npm:** https://www.npmjs.com/package/svelte-exmarkdown ## Feature comparison | Feature | @humanspeak/svelte-markdown | svelte-exmarkdown | Notes | | --- | --- | --- | --- | | Svelte 5 Compatibility | Yes | Yes | | | TypeScript Support | Yes | Yes | | | Parsing Engine | marked | unified/remark/rehype | | | Custom Renderers | Yes | Yes | | | Token Caching | Built-in LRU cache | No | | | HTML Tag Control | 83 tags with allow/deny | Via rehype plugins | | | LLM Streaming Mode | writeChunk() / resetStream() | No | svelte-exmarkdown is a runtime renderer, but its upstream docs do not describe a streaming-specific incremental mode. | | Streaming HTML Output | Partial blocks reconcile when arrives | No | No documented streaming pipeline; partial HTML blocks during streaming aren’t reconciled into nested structures. | | Plugin System | Marked extensions | Remark/rehype plugins | | | Snippet Overrides | Yes | No | | | HTML Renderers | 83 dedicated components | Generic element handling | | | Math (KaTeX) | Built-in extension (markedKatex) | Via remark-math + rehype-katex | | | Diagrams (Mermaid) | Built-in extension (markedMermaid) | Via rehype-mermaid | | | Dependency Surface | marked-based renderer | unified + remark + rehype pipeline | | | Marked Extensions | Yes | No | | ## Svelte Markdown strengths - Svelte 5 runes-native — built for runes, not retrofitted - TypeScript-first with full type safety - Built-in token caching (50-200x faster re-renders on repeated content) - LLM streaming with imperative writeChunk() / resetStream() API - 24 markdown renderers + 83 HTML tag renderers — every override is a Svelte snippet - First-class extensions: KaTeX math, Mermaid diagrams, GitHub alerts, footnotes - Opt-in Shiki syntax highlighting (streaming-compatible, tree-shaken from core) - Built-in XSS protection — protocol allowlist, event-handler stripping, attribute sanitization - Allow/deny utilities (allowHtmlOnly, excludeRenderersOnly, etc.) for fine-grained control - Drop-in component — works anywhere in your Svelte app - Svelte 5 snippet overrides — customize rendering inline - 83 dedicated HTML tag renderers (not generic) - Smaller bundle — marked is lighter than unified stack ## svelte-exmarkdown strengths - Built on unified ecosystem — access to hundreds of remark/rehype plugins - AST-level transformation capabilities - Plugin architecture designed for extensibility - Active maintenance and Svelte 5 support ## Svelte Markdown limitations - Smaller community (newer project) - Runtime-only (no build-time optimization) - No direct access to remark/rehype plugin ecosystem ## svelte-exmarkdown limitations - No built-in token caching - Larger bundle (unified + remark + rehype) - No snippet override support - Fewer dedicated HTML tag renderers ## Verdict Choose svelte-exmarkdown if you are invested in the unified/remark/rehype ecosystem and need specific plugins from that world. Choose @humanspeak/svelte-markdown for a lighter, faster option with built-in caching, snippet overrides, and comprehensive HTML tag handling. ## Keywords svelte exmarkdown, svelte markdown component, svelte-exmarkdown vs svelte-markdown