Show HN: Make PDFs look scanned (CLI or in the browser via WASM)

overflowy 105 points 49 comments June 20, 2026
github.com · View on Hacker News

I made this because the online "make my PDF look scanned" tools want you to upload your file to their servers, which feels sketchy at best. Also, I wasn't happy with the output they produce, I wanted something that looks realistic.

Discussion Highlights (14 comments)

costabrosky

Useful tool

mysterydip

I’m all for fun side projects, so don’t take this the wrong way. Does this have a practical use case? Like are people actually wanting to make their PDFs less legible? Usually I’m trying to do the opposite, clean up my scanned-in documents.

echoangle

If you’re interested in another suggestion: maybe allow image output too since that seems to be one of the steps in your pipeline? Maybe for some people using the jpg or a png directly is better than the final pdf.

ashton314

This needs a flag to insert random blank pages

wan888888

I'm having a similar use case from time to time, I just use imagemagick magick -density 150 input.pdf \ -colorspace Gray \ -virtual-pixel White -background White \ -rotate 0.7 +repage \ -attenuate 0.45 +noise Gaussian \ -blur 0x0.4 \ -brightness-contrast -5x12 \ -compress jpeg -quality 78 scanned.pdf

carsonye

Is there any good tool that does the opposite — turning scanned documents into clean PDFs? I’ve had that need recently.

colesantiago

Thank you for making this a free tool. There are too many PDF tools that are unnecessarily paywalled, or have a paid tier that don't make any sense. We need more tools from paid ones that should be completely free and OSS.

sublinear

In the example image, the edge gradient bevels give it away. There might be extra stuff that can be done to remedy that with this tool, but I'm not sure I'd ever use this anyway.

kccqzy

I just display the PDF on my monitor and use my phone to take a photo of it. Scanner apps are good at eliminating moire patterns while accentuating the dust on my monitor. It looks highly realistic.

janoelze

But… does it look scanned? https://i.imgur.com/ENKZV7s.png

Cbagenal

cool idea, looks sooo realistic

hk1337

Basically, you’re converting it to an image-based PDF so they cannot just scrape the text off of it but would have to use OCR?

recroad

This has been working for me https://lookscanned.io/en/scan

Phoenixhq

It's pretty good, but there seem to be some similar products on the market that can convert locally without uploading.

Semantic search powered by Rivestack pgvector
11,093 stories · 104,372 chunks indexed