{"slug": "latex-renderer", "title": "LaTeX renderer", "summary": "Simon Willison released a LaTeX renderer at tools.simonwillison.net/latex that stores LaTeX source in the URL fragment, letting rendered documents be bookmarked and shared as links. Willison built the tool with Claude Code (Opus 5.5 Extra), inspired by Paul Ford and Aboard Foundry's Tiny Little Office, which uses the same URL-fragment approach and an llms.txt file that Claude used to generate a shareable deck link. The renderer runs LaTeX in an iframe sandbox for XSS protection and supports loading LaTeX from a URL or Gist, plus a compressed-fragment prefix using a LaTeX-specific compression dictionary.", "body_md": "**Tool:** [LaTeX renderer](https://tools.simonwillison.net/latex)\n\nInspired by Paul Ford and Aboard Foundary's new web app [Tiny Little Office](https://tinylittleoffice.com/), which provides a suite of web app content editors (a Word Processor, Outliner, Presentation Builder, Spreadsheet, Calculator, Drawing Tool, Diagram Maker, Animator, Calendar, and Trip Planner).\n\nTiny Little Office's signature trick is to store all of the document data in the `#fragment` section of the URL, so every document created using it becomes a bookmarkable and shareable link.\n\nIt also has [an llms.txt file](https://tinylittleoffice.com/llms.txt) telling agents how to construct URLs that will render as documents. Claude [used that file](https://claude.ai/share/239301ff-edde-420e-b433-b9c16fe40a6c) to generate [this link to a deck](https://tinylittleoffice.com/#/v1/deck/zXVVdb9tGEHznr1hED2kBSbZcO4UFtIHTuCgQtylstwH6Uq7Io3gRdcfeHS1T_fjtnV1Ssp038r52d2Z2djabZcmmxizpJ78jpnvrerqxCUv0sapsYaixbkM7HzYxS7XZ4ujWls6u65SlwC7aZL1bUmxsabIZHpxMaCmXlnRfG9rVHm~Vvui2xiWykfDK8Ojfc439b5bN6BdP0YQHE6bkPJWceMXR6A8Xhe9cwqFr7Peptm5NXCUT9Kl8klNM3EeyjnrfBVoFv8Nj2TGbaDgU9ZKuHCe_7clXKFVSkMh5Qs2Nluy14nnhtyeTk4fFSWmKzUn_7e~f5_N5LkcfFvlSg1Y~bDkR8omoXrbkLDZ3tS1q4rYl3xqHnCTvvB~vbX2J2k1C7rI8vjzsHSCaEuK3wcRoSmJXknEFrpVZ9r0CWgVeK5QDBBOB1BlkAgCxmry~dgAz~hePj0i1wT5wMnIY_Ohl0FQ~cTN_Aq~yIo~7ZFpaoL5gcc8iOg6bx5QdaHlB8f3Nxykg_pnDpvQ7Rw8cLCuFdyKTSLEF4uQd5QiTS0gTsftDzSHFKZWBd2A5av3sLLAGzPgNqB94AJlV44uN3LmvEVDQl8C88l2iBX14JyS3DUMTY5pjOS0XG14fKjqDcP_qjNlLTVLLLe_o_fWPN1f319MBSN4a4mbtUXi9lbL3ttW81vgQFvcgcIg0XjwwPv7SDjeBhnBqEpW2kGI49HIu4Bw0fqAcGwRdcdMc6O6fXdAKAcBurA9dWSrYR_AjddGIuH1ayqNbvHft1o2N9RTqc5IIUi~5J4fCAHVEXC5jbZBa1TkNheUjdbF3iR_ndGtaw3i_9RYcr1jwdtAPaLQuJrwhGa2MNGdsTdOAI3DxTEii4hH2b2AivFEd_XZ7M4tcGQH_XZ~gjZVB4oak_9~cd6FZ0htaWQkNmRZQCBdj_1zN_iCe7el0dpkLWZDTf7kWmP~p_Yq_YMBNYQZpd7HjBprLp8OpmViHbRpSDKiCDNWLBo9xxpQatQCyM21DLD8rSNQ6uBwKtgU71eGUVj1Fu0dJeZ4rsnplPL7ioL93CTKkf4aiMyFRhIqFi_PLs~y9qRp0aDmIp8fy4vzsIrsR32y5bzzwxtrl6UKCiFgu5hejLNSKozTg2EdjGz11EioV2kYXpM6VgPZsenp6~gSwaKP2IcF_fLeuxfKgoJjkRBKHi8~43Zh~SZ_qXgyYAMTrpJAKwQDD9ErvJ5Qi7amGdBT1lGpuKl1cKf~DwhDDDTxoj3N6HeFVvfSR9pp1ChBVbJs4oPSqtLA3uAN8zWMjqExfaZshma~~zqVmbWqYGN7j1s4_q3l4MSXG7BunwnFwpCQ~tKTrRwy7KI4l940rdXS8BUK7fLR6HlxI29ylIfH8bZkfJ4HYrSRyGBfztk2PJzIBSFpNOI2jtaLLYbs4~KsWK~MGpgAz10G8pHyYTRP0_Xc5EOm~0CmE89L2ihrnoVUxkfRi8sJzHYTonVE_Ua0cR3Shm1H9CXPLNP2XjovGNI3M0_1smG4C4P8) that explains how the URL format works:\n\nTiny Little Office inspired me [to have Claude Code](https://claude.ai/code/session_017KJrPqqWVHLqr4E7TLPnpt) (Opus 5.5 Extra) build a similar tool that works with LaTeX. Here's the sequence of prompts I used:\n\n`I want a tool where you can link to it with a fragment hash #code-here and it treats that code as LaTeX and renders it really effectively. It should also support a prefix which means the latex is compressed with a custom compression dictionary optimized for latex. Use the best available latex render library from a CDN (consider WebAssembly too). If loaded without a fragment hash show an editor you can paste latex into and then toggle to a \"rendered\" view. That rendered view should be bookmarkable. The #fragment view should let you switch to edit source too.`\n\nSince it was working in [my tools repo](https://github.com/simonw/tools) I told it to take inspiration from the `