Choosing an image format: JPEG, PNG, WebP or AVIF
3 min read · Updated 3 October 2026
Every image format is a trade-off between file size, quality, transparency and how widely it is supported. Picking the right one usually saves more space than any compression setting.
The short answer
| You have | Use | Why |
|---|---|---|
| A photo for email, forms or printing | JPEG | Opens everywhere; good quality at small sizes |
| A photo for a website | WebP or AVIF, with JPEG as a fallback if you must support very old browsers | 25 to 50 % smaller than JPEG at similar quality is common |
| A screenshot, diagram or text-heavy image | PNG (or lossless WebP) | Sharp edges and text stay crisp |
| A logo or icon | SVG if you have it; otherwise PNG | Scales without blur; transparent background |
| Something that needs transparency | PNG, WebP or AVIF | JPEG has no transparency |
| An animation | A video (MP4/WebM) where possible; GIF only when it must be a GIF | GIF is limited to 256 colours and is large |
Lossy and lossless
Lossy formats (JPEG, lossy WebP, AVIF) throw away detail the eye is unlikely to notice. Each time you save a lossy file again, a little more detail is lost, so keep an original and export from it.
Lossless formats (PNG, lossless WebP) keep every pixel. They are larger for photos but ideal for screenshots, where lossy compression creates visible smudges around text.
Quality settings
Lossy encoders take a quality number, usually 0 to 100. It is not a percentage of anything; it controls how aggressively detail is discarded. For photos, quality 75 to 85 is a good default. Below about 60, blocky artefacts and colour banding become visible, especially in skies and gradients.
If a form demands a maximum size (say 200 KB), it is better to search for the highest quality that fits than to guess. The target-size compressor does exactly that, and only reduces dimensions when quality alone cannot reach the target.
Dimensions matter more than you think
A 12-megapixel phone photo (4032 × 3024) shown at 800 px wide on a web page wastes most of its pixels. Resizing to the size it will actually be displayed (doubled for high-density screens) often cuts the file size by 80 % before any compression. Use the batch image resizer first, then compress.
HEIC photos from iPhones
iPhones save photos as HEIC by default. It is efficient, but many websites and Windows apps cannot open it. Convert to JPEG when you need to share or upload; the image converter does this on your device.
Metadata
Photos carry EXIF metadata: camera model, date and often GPS coordinates. Converting a file usually drops most of it, but if you are sharing originals, check and remove location data with the metadata tool.