The Privvert Blog
Long-form, no-fluff writing on file privacy, format internals, and how to do everyday file tasks without handing your data to a stranger. Read our editorial guidelines for how we research, source, and verify what we publish.
PDF redaction done right: why black rectangles in Word and Preview don't work
Drawing a black box over a name in Word, Preview or Acrobat's markup tools does not delete the text underneath - it sits on top of it, fully selectable and copyable. Here is what real PDF redaction looks like, the well-documented incidents that prove the point, and how to do it locally without uploading the file.
WebP vs JPEG vs AVIF in 2026: which image format to actually use
Three image formats, three sets of trade-offs, and a lot of confident-sounding advice on the internet that is out of date or wrong. Here is what each format actually does, where it wins, where it loses, what current browsers and platforms support, and how to pick without overthinking it.
How to remove metadata from photos before sharing
Your photos carry hidden data: GPS coordinates, device serial numbers, timestamps, and more. Here is exactly what is in there, why it matters, and how to strip it - on every platform, without uploading anything.
The hidden risks of online file converters (and how local processing fixes them)
Free online converters look harmless. Behind the scenes, your file is uploaded, processed on someone else's server, logged, often retained, and sometimes scanned or sold. Here is what actually happens - and what to use instead.