Practical guides to files and privacy
Each guide answers one specific question and takes you to the tool that solves it, with no detours.
Images
- How to redact a screenshot safely, so it cannot be undoneBlurring an account number does not hide it, and some editors keep the original image. What goes wrong when redacting screenshots and how to do it properly.
- How to reduce a photo to 100 KB (or whatever size you need)Application forms often want photos under 100 or 200 KB. Here is how to get there without losing sharpness and without uploading the photo anywhere.
- How to resize an image without losing qualityWhat resizing really means, why shrinking is safe and enlarging is not, and how to get a photo to exact dimensions without stretching it.
- How to send a photo of your ID or passport more safelyLandlords, banks and online services ask for a copy of your ID. What lowers the risk of impersonation, and how to prepare the photo without uploading it.
- JPG vs PNG vs WebP: which image format to use and whenWhen each format makes sense, why a JPG screenshot looks blurry and a PNG photo is huge, and how to convert between them without uploading your images.
- How to merge PDF files into one without uploading themThe most popular PDF sites upload your documents to their servers. Here is how to combine payslips, contracts or an ID into one file without them leaving your device.
- How to send only some pages of a PDFThey asked for the signature page or one specific sheet, and you have the whole document. How to extract those pages into a new PDF without uploading it.
Privacy
- How long it really takes to crack a passwordThose "your password would take X years" charts are often misleading. How password crackers actually work, and what makes a password hold up or fall in seconds.
- How to check whether your password was leaked, without revealing itYou can check whether a password appears in known breaches without sending it to anyone. Here is how the technique works and what to do if yours shows up.
- How to remove the location from a photo on iPhone, Android or PCPhone photos store the exact coordinates of where they were taken. Here is how to check whether a photo carries them and how to remove them before sharing.
- What EXIF metadata in a photo is, and what it reveals about youEvery photo stores invisible data such as the location, the phone it was taken on and the exact time. What it contains, who can read it and when to remove it.
- What fbclid, utm and si= in links mean, and how to remove themLinks copied from social media and shops carry identifiers that say where you came from and sometimes who shared them. What each one means and how to strip it.