Contact
Bug reports, feature requests, "this tool ate my PDF" stories, and "this conversion is wrong" reports are all welcome. The fastest way to get my attention is email with a small sample file attached (one I can use to reproduce — preferably one I can keep, but not required).
Reporting a bug
A useful bug report has three things: (1) the URL of the tool you used, (2) what you expected vs. what happened, and ideally (3) a sample file that triggers it. The third one is the most valuable — without a reproducer, I'm guessing.
Files attached to email reports are deleted once the bug is fixed (or once I confirm I can't reproduce it). If your file contains anything sensitive, please redact or synthesise an equivalent; the privacy policy on the site only covers what happens in the browser, not what you choose to send me.
Requesting a tool
Before suggesting a new PDF tool, check the homepage and the footer to make sure it's not already there in slightly different form. The tools that currently exist solve problems I've personally hit; the bar for adding more is "useful enough that I'd reach for it again next month."
What this site doesn't do
It does not OCR scanned PDFs (yet — Tesseract.js is heavy and would slow page loads for everyone), does not bypass user-password encryption, and does not "compress" PDFs in a way that's worth shipping (browser-side recompression can't compete with Ghostscript / qpdf). Each of those is a deliberate gap, not an oversight.
Other sites
Sister tools for adjacent file formats: csvkit.org (CSV), jsonlkit.com (JSONL / JSON Lines), tomlkit.org (TOML), geojsonkit.org (GeoJSON). Same browser-only philosophy.