Guides
Which format to choose, how to keep quality when converting, and how to fix files that won't open.
General
- How to Change a File Type or Extension
How to see and change file extensions on Windows, Mac, iPhone and Android, when renaming a file works, and when it needs converting instead.
Image
- Image Formats Compared: JPG, PNG, WebP, AVIF, HEIC, SVG
A practical guide to choosing between JPG, PNG, WebP, AVIF, HEIC and SVG for photos, graphics, websites, sharing and printing, with clear rules.
- Image Size and Resolution: Pixels, DPI and What You Need
What image resolution really means, how pixels relate to DPI and print size, and how many pixels you need for screens, social media and printing.
- How to Convert iPhone Photos to JPG
Five ways to get JPG files from your iPhone, from changing a camera setting to converting HEIC photos and PNG screenshots in Safari, with no app needed.
- How to Reduce Image File Size Without Losing Quality
Five ways to make image files smaller, in the order that saves the most space, with the settings to use and how to avoid visible quality loss.
- How to Save a Picture as JPG on Any Device
Step-by-step ways to save any picture as a JPG or JPEG file using Paint, Preview, Finder, your phone or a browser, plus the quality setting to choose.
- Why Images Download as WebP (and How to Get JPG)
Why "Save image as" gives you a WebP or AVIF file, why the website is doing it, and four ways to end up with a normal JPG or PNG instead.
- How to Turn a Scanned Document Into a PDF
How to scan paper documents into a clean PDF with your phone or a scanner, combine several pages, fix sideways pages and keep the file small.
Audio
- How to Convert CDA to MP3 (Why CDA Files Won't Play)
CDA files aren't audio, they're shortcuts to tracks on an audio CD. Here's how to rip a CD to MP3 on Windows and Mac, and why copying CDA files never works.
- How to Extract Audio From a Video
Get the sound out of a video as MP3 or WAV on Windows, Mac, iPhone or Android, using your browser, VLC or iMovie, with tips for long and large files.
- How to Convert Voice Memos to MP3
Get voice memos and recordings off your phone or computer and convert them to MP3, with steps for iPhone Voice Memos, Android recorders, Mac and Windows.
- WAV vs MP3: Quality, File Size and Which to Use
WAV and MP3 compared in plain terms, covering sound quality, file size and compatibility, with clear rules for when to use each and how to convert between them.