Pandoc in the Browser with WASM

#1

Post by vinnyhaps » Thu, Feb 12, 2026, 12:10 PM UTC

Pandoc in the Browser with WASM
discourse.haskell.org

Re: Pandoc in the Browser with WASM

#2

Post by westurner » Thu, Feb 12, 2026, 6:37 PM UTC

From the pandoc release announcement: https://github.com/jgm/pandoc/releases/3.9 :

> Starting with this release, pandoc can be compiled to WASM, making it possible to use pandoc in the browser. A full-featured GUI interface is provided at https://pandoc.org/app

Re: Pandoc in the Browser with WASM

#3

Post by westurner » Thu, Feb 12, 2026, 6:40 PM UTC

westurner wrote: post #2

From the pandoc release announcement: https://github.com/jgm/pandoc/releases/3.9 : > Starting with this release, pandoc can be compiled to WASM, making it possible to use pandoc in the browser. A full-featured GUI interface is provided at https://pandoc.org/app

Pandoc in WASM probably makes it possible to add jupytext pandoc markdown support to jupyterlite?

Re: Pandoc in the Browser with WASM

#4

Post by hbcondo714 » Thu, Feb 12, 2026, 7:00 PM UTC

> ERROR: Unknown input format pdf Pandoc can convert to PDF, but not from PDF

Darn

Re: Pandoc in the Browser with WASM

#5

Post by iib » Fri, Feb 13, 2026, 12:06 AM UTC

This is really nice to know. I remember trying to compile pandoc to Wasm after finding out that ghc had Wasm support, hitting all kinds of problems and then realising that there was no real way to post an issue to Haskell's gitlab repo without being pre-approved.

I guess now with LLMs, this makes more sense than ever, but it was a frustrating experience.

Re: Pandoc in the Browser with WASM

#6

Post by rustyhancock » Fri, Feb 13, 2026, 8:37 AM UTC

iib wrote: post #5

This is really nice to know. I remember trying to compile pandoc to Wasm after finding out that ghc had Wasm support, hitting all kinds of problems and then realising that there was no real way to post an issue to Haskell's gitlab repo without being pre-approved. I guess now with LLMs, this makes more sense than ever, but it was a frustrating experience.

> no real way to post an issue to Haskell's gitlab repo without being pre-approved.

This is so on brand for Haskell people I love it.

Re: Pandoc in the Browser with WASM

#7

Post by fiddlosopher » Fri, Feb 13, 2026, 9:45 AM UTC

The web app can be found at https://pandoc.org/app . This has almost the full power of the command-line app, subject to the limitations imposed by the WASM sandbox. Thus:

- the app cannot fetch resources using HTTP

- JSON filters are not supported, as they involve external programs

- Lua filters are supported, but only if they don't try to do system IO operations or run external programs

- Output to PDF is supported only via Typst (using the WASM version of Typst).

Re: Pandoc in the Browser with WASM

#8

Post by tome » Sat, Feb 14, 2026, 4:40 PM UTC

rustyhancock wrote: post #6

iib wrote: post #5

This is really nice to know. I remember trying to compile pandoc to Wasm after finding out that ghc had Wasm support, hitting all kinds of problems and then realising that there was no real way to post an issue to Haskell's gitlab repo without being pre-approved. I guess now with LLMs, this makes more sense than ever, but it was a frustrating experience.

> no real way to post an issue to Haskell's gitlab repo without being pre-approved. This is so on brand for Haskell people I love it.

Really, why? What do you mean? The reason for manual approval of accounts was to defeat spammers.