Image Formats Explained: JPEG, PNG, WebP, AVIF in 2026
Four formats cover 95% of practical image needs in 2026. Here is what each is for, where each wins, and the decision tree for picking one.
Most image-format confusion comes from a simple problem: each format was designed for a different problem, and the original problem isn't always the one you have. This guide is a plain-English reference for the four formats that matter in 2026.
The four formats that matter
| Format | Built for | Best at | Worst at |
|---|---|---|---|
| JPEG | Photographs (1992) | Universal compatibility | Transparency, sharp edges |
| PNG | Lossless graphics (1996) | Transparency, screenshots | Photo file size |
| WebP | Better than JPEG (2010) | Web delivery | Pro-tool integration |
| AVIF | Better than WebP (2019) | Smallest possible | Encoder speed |
Everything else (GIF, TIFF, HEIC, BMP, JXL) either serves a niche or is in transition. These four cover 95% of practical needs.
How they compare on file size
A 4000×3000 reference photograph saved at visually-equivalent quality:
- JPEG q85: 1.8 MB (the reference)
- PNG (lossless): 8.4 MB
- WebP q80: 1.2 MB (~33% smaller than JPEG)
- AVIF q60: 720 KB (~60% smaller than JPEG)
For a 1080×1080 graphic with transparency:
- PNG-32: 220 KB
- WebP lossless: 140 KB
- AVIF lossless: 120 KB
The pattern: newer formats compress better. The trade-off: newer formats are slower to encode and were unsupported in older software.
When to pick each format
Pick JPEG when:
- The destination is non-web (email, PDF, print, old software)
- Compatibility outweighs file-size savings
- You're round-tripping through tools that may not speak WebP/AVIF
Pick PNG when:
- You need lossless and the file will be edited again
- Screenshots: PNG is the right answer for any screen capture
- Pixel art at small sizes
- Diagrams, flowcharts, anything with sharp edges and flat colour
Pick WebP when:
- The image is going to a web page
- You want JPEG-quality at ~33% smaller files
- You need alpha transparency at photo sizes (PNG transparency is expensive)
- Encoder speed matters (WebP encodes nearly as fast as JPEG)
Pick AVIF when:
- The image is large enough that the 50% savings matter
- The destination is a website or app (full modern browser support)
- You can tolerate 5-10× JPEG's encode time
- Bandwidth costs are a meaningful expense
A simple decision tree
- Going to the web? Try AVIF first. Fall back to WebP if encode speed matters. Fall back to JPEG only if you support pre-2018 browsers.
- Needs transparency? WebP for web, PNG for editor round-trip.
- Screenshot or graphic? PNG.
- Email / print / archive? JPEG.
A note on HEIC
HEIC is technically a fifth format worth knowing because iPhones default to it. For practical purposes, treat HEIC as "JPEG, but better, and only Apple devices read it." Convert to JPEG when sharing outside Apple devices, via HEIC to JPG converter handles the conversion locally in your browser.
How to convert between formats
OmegaPix runs every conversion client-side via WASM, so your images never upload:
- Image Compressor handles all four formats
- PNG to WebP, AVIF Converter, HEIC to JPG for specific conversions
- JPG Compressor for JPEG re-compression
Try Image Compressor, free in your browser
No uploads, no account. Your images never leave your device.
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