Blog
Guides to images and PDFs, loans and interest, crypto and exchange spreads — every tool runs in your browser, so your files never leave the device.
Annuity or Declining Payments: Which Loan Costs Less, and by How Much
Same loan, two schedules. Worked examples on a 20,000 loan and a 300,000 mortgage: what the declining schedule saves, what it asks up front, and a third option most borrowers miss.
Paying Extra on a Loan: Shorten the Term or Lower the Payment? Worked Numbers
The same extra money, two ways to apply it, very different savings. Worked on a 300,000 mortgage: why the term wins, why paying early matters more than paying a lot, and when the lower payment is still right.
Why Crypto Arbitrage Almost Never Works: One Week of Our Scanner in Numbers
A spread between two exchanges looks like free money. Our paper bot watched them for a week: 20 trades, 217,989 refusals, and the reasons behind each refusal.
APY and APR in Staking: What the Number on the Banner Means, Worked Out
The same yield can be written two ways and mean different money. The conversion in a table, what a platform fee and a price drop do to it, and how to compare two offers.
How to Compress an Image to Under 100 KB — and What Is Left of It (Measured)
Hitting a 100 KB limit is easy; keeping the photo decent is the real question. What 20, 50, 100 and 200 KB leave of 20 ordinary photos, and how to choose.
How to Open and Convert HEIC Files (iPhone Photos) on Windows
What HEIC is, why a computer may refuse to open it, how to convert it to JPG in the browser without uploading, and how to make the iPhone shoot JPEG instead.
How to Combine Several Images into One PDF — and What Happens to Their Quality
Turn photos, scans, receipts and screenshots into one ordered PDF in your browser, and choose the preset that keeps them readable without making the file huge.
Passport Photo Size in Pixels: 35×45 mm and 2×2 in, and When Not to Resize
The arithmetic from millimetres to pixels, what our resizer makes of an ordinary photo, and why the official photo rules have to be read first.
JPG vs PNG vs WebP: Which Format to Use — Measured on 20 Photos and 10 Screenshots
What each format is good at, with our own numbers: how file size changes when photos and screenshots move between JPG, PNG and WebP.
Square, Portrait or Story: What Cropping to 1:1, 4:5 and 9:16 Takes from a Photo
Every social format is a shape, and every shape cuts something off. How much of an ordinary photo survives each crop, and how to keep what matters.