PDF tools we use

pdfium-cli

See https://github.com/klippa-app/pdfium-cli

Binary vs. WebAssembly performance:

time pdfium render sample.pdf sample-%d.jpg
Rendered page 1 into sample-1.jpg
pdfium render sample.pdf sample-%d.jpg 0.93s user 0.03s system 85% cpu 1.128 total

time ./pdfium-webassembly-linux-amd64 render sample.pdf sample-%d.jpg
Rendered page 1 into sample-1.jpg

real	0m1.479s
user	0m1.442s
sys	0m0.036s

tesseract

We use https://github.com/tesseract-ocr/tesseract