I used existing wasm compiles of PDF tools. This use of wasm is pretty awesome to me - I often end up working on very restricted desktop clients with little customization possible, but they always let me run a browser.
That website loads WASM by embedding base64 in the HTML, which is good for saving it as a single file but horrible for WebKit support ("The operation is insecure", it complains), transfer size, and speed.
https://kc0bfv.github.io/WASM-PDF-Combiner/
I used existing wasm compiles of PDF tools. This use of wasm is pretty awesome to me - I often end up working on very restricted desktop clients with little customization possible, but they always let me run a browser.