One site, no uploads
Most free tool sites work the same way: you upload your file, a server processes it, and you download the result. That is fine for a holiday photo. It is not fine for a passport scan, a signed contract or six months of bank statements, and those are exactly the files people most often need to resize, convert or compress.
The Daily Toolbox does the work in your browser instead. The page loads the tool once; after that, your file is read, processed and saved on your own device. You can disconnect from the internet after the page loads and every tool keeps working, which is the simplest proof that nothing is being sent.
Why upload forms are so fussy
A government portal that rejects your photo is usually running an automated check on three things: the pixel dimensions, the file format and the byte count. It cannot explain itself, and some, the US DS-160 is the notorious example, show no error at all. Our requirements database records the exact numbers for each portal, and the photo maker applies every one of them at once.
Calculators you can check
Most calculator pages hand you a number and nothing else. If the number is wrong, a stale tax rule, a rounding shortcut, the wrong compounding convention, you have no way to notice. Every calculator here states its formula, walks through a worked example and names the convention it uses, and the maths is tested against published bank tables and Excel's own functions. Read more on the methodology page.
Results are estimates from the numbers you enter, not financial advice. For decisions with real stakes, treat them as preparation for a conversation with a qualified adviser.