Guides
Image tips & guides
Practical guides to compressing, resizing, converting and optimising images — plus QR codes, barcodes and keeping your photos private.
Processed locally in your browserHow to compress images without losing quality
"Without losing quality" is not quite possible, and not quite necessary. Here is what compression really throws away, why 80 is the number you keep seeing, and how to hit an exact file size when a form insists on one.
Read the guideJPG vs PNG vs WebP vs AVIF: which image format should you use?
Four formats, one decision, and a lot of bad advice online. Here is what each one is actually for, what happens to transparency when you convert, and the two rules that cover almost every case.
Read the guideHow to resize images without stretching, cropping or blurring them
Most resizing problems come down to one thing: the shape you asked for doesn't match the shape you have. Here is what each fit mode does about it, and how to pick dimensions that are actually right.
Read the guideCropping and aspect ratios: getting the framing right
Cropping and resizing solve different problems, and using the wrong one is why your photo came back squashed or missing someone's head. Here is which to reach for, and the ratios worth memorising.
Read the guideHow to remove an image background (and what to do next)
Cutting out the subject is the easy part now. The part that trips people up is everything after: which format keeps transparency, why the edges look wrong, and how to put the cutout on a clean background.
Read the guideQR codes and barcodes that actually scan
A code that scans on your monitor can fail completely on a printed label. Error correction, quiet zone, contrast and physical size decide it — and three of those are easy to get wrong while making it look nice.
Read the guideWhat your photos reveal: EXIF data and how to remove it
A photo is not just pixels. It usually carries the camera, the lens, the exact timestamp and, very often, the GPS coordinates of where you were standing. Here is how to check, and how to remove it.
Read the guideWhich ImageDoctor tool should you use? A guide to all of them
Thirty-odd tools is a lot to scan. This is the map: what each one is actually for, which to reach for when two overlap, and how browser-based editing compares with the alternatives.
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