Guides
Every guide here exists because someone hit a wall — a form that rejected a file, a photo that would not open, a size limit with no explanation. No filler, no affiliate links, no sign-up.
File size and upload limits
- How to Compress an Image to an Exact File Size
Upload forms rarely explain their limits. Here is how the 200 KB and 2 MB caps actually work, and how to land under one.
- Why Is My Image File So Large? Six Causes and Six Fixes
A screenshot of text has no business being 8 MB. Usually one of six specific things is to blame.
- Passport Photo Size Requirements: Pixels, Format and 240 KB
600×600 to 1200×1200 pixels, square, JPEG, 240 KB or less. What each rule means and how to meet all four at once.
- How to Combine Photos into One PDF
Why offices ask for a PDF instead of ten JPGs, and how to build one that fits inside Gmail's 25 MB ceiling.
Choosing a format
- Why Your iPhone Photos Won't Open on Windows
The file is not corrupted and your phone is not broken. It is a format standoff that has lasted nine years.
- HEIC vs JPG: Which Should You Keep Your Photos In?
HEIC is genuinely the better format. That is not the same as it being the better choice for you.
- WebP vs JPG vs PNG vs AVIF: A Decision Guide
Four formats, one decision. The answer depends on where the file is going, not on which is technically best.
- What Happens to Transparency When You Save a PNG as JPG
Transparent areas turn white, or sometimes black, and there is no way to get them back. Here is why, and what to do instead.
Size, shape and orientation
- How to Resize an Image Without Losing Quality
Making an image smaller is nearly free. Making it larger is where the honest answer disappoints people.
- Aspect Ratio Explained: Why Photos Get Cropped Wrong
Your head keeps getting cut off in the thumbnail. The reason is arithmetic, and it is predictable.
- Instagram Image Sizes, and the Rules for Everywhere Else
Current pixel dimensions, plus the one rule that outlives every table of numbers like this.
- Why Your Photo Appears Sideways After Uploading
The photo is upright on your phone and on its side everywhere else. One hidden number explains it.
Privacy
- The GPS Coordinates Hidden in Your Photos
Most phone photos carry the exact spot they were taken, accurate to a few metres. Including the ones taken at home.
- Are Online Image Tools Safe? How to Check for Yourself
Most image sites upload your file to a server. Here is how to tell which ones do, without taking anybody's word for it.