JPG vs PNG vs WebP vs AVIF: which image format to use, and when
A plain guide to the four image formats that matter in 2026: what each is good at, the file-size difference on the same photo, when transparency matters, which formats portals and WhatsApp accept, and how to convert between them without uploading.
· 3 min read · 923 views · by the Cortex Digital Hub team
JPG, PNG, WebP, AVIF, HEIC, any direction. Runs in your browser, batch of 50, nothing uploaded. Free.
Convert between formats → Opens Image Converter · runs in your browser
Four formats cover almost every image you will ever save, and picking the wrong one costs either file size or compatibility. This is the short version with numbers.
The four formats in one table
| Format | Best for | Transparency | Typical size (same 12 MP photo, good quality) | Opens everywhere? |
|---|---|---|---|---|
| JPG / JPEG | Photos you send or upload | No | 1.5–3 MB | Yes |
| PNG | Logos, screenshots, diagrams, text, anything transparent | Yes | 8–20 MB for a photo; small for graphics | Yes |
| WebP | Photos and graphics on websites | Yes | 1–2 MB | Browsers yes; some apps no |
| AVIF | Websites where every KB matters | Yes | 0.6–1.2 MB | Current browsers; fewer apps |
HEIC, the iPhone default, is a fifth: very small, excellent quality, and opens almost nowhere outside Apple. It is covered in HEIC explained.
JPG: the default for photos you give to people
JPG throws away detail the eye does not notice (lossy compression) and does it well on photographs. Every phone, portal, e-mail client, printer and government form accepts it. Its two weaknesses: no transparency, and it slowly degrades if you edit and re-save many times. Save a master once, then export JPGs from it.
Quality setting: 80–85% is the sweet spot. Above 90 the file doubles for nothing visible; below 70 you start to see blocks in smooth skies and skin.
PNG: the format for sharp edges and transparency
PNG is lossless: what you save is exactly what you get back. For a logo, a chart, a screenshot of text or a product cut-out with a transparent background, it is the right choice and the files are small because flat colours compress well. For a photo it is the wrong choice: three to eight times the size of a JPG with no visible gain.
The common mistake: saving a photo as PNG "for quality". The quality is the same as a 95% JPG; the size is not.
WebP: the format for your website
Google's format, now supported by every browser and most phones. Same photo, same visible quality, 25–35% smaller than JPG, and it supports transparency, so it replaces both JPG and PNG on a website. Use it for anything you publish on the web.
Do not use it for files you send to people: some e-mail clients, Windows photo viewers and nearly all government portals still reject it.
AVIF: smaller still, less compatible
AVIF compresses better than WebP (often half the size of JPG) and looks cleaner at low sizes. All current browsers render it; many desktop apps and older Android phones do not. It is a good choice for images on a site you control, with a JPG fallback, and a bad choice for anything else.
Choosing in practice
- Uploading to a form or portal: JPG, under the stated KB limit. Use the image compressor with a target size.
- Sending on WhatsApp or e-mail: JPG at 1080–1600 px.
- Logo, icon, signature, chart, screenshot: PNG.
- Product photo with the background removed: PNG (transparent) for the website or catalogue, JPG on white for marketplaces that require it.
- Images on your own website: WebP, with AVIF if your platform generates it automatically.
- Printing: JPG at 90% or PNG, at 300 dpi for the print size.
Converting without losing anything
Converting between formats is a one-way street in one direction: JPG → PNG gives you a bigger file with the same JPG artefacts baked in; PNG → JPG loses transparency (it is flattened on white) and some detail. Convert from the best original you have, once.
The Cortex image converter converts JPG, PNG, WebP, AVIF, HEIC and others in any direction, keeps transparency where the target supports it, and handles 50 files at a time with a ZIP download. It runs in the browser, so nothing is uploaded and large batches are not slow. For specific pairs there are direct pages: HEIC to JPG, PNG to JPG, WebP to JPG, JPG to WebP.
Frequently asked questions
Is WebP better than JPG?
For the web, yes: 25–35% smaller at the same visible quality, with transparency and animation. For sharing files with people, JPG still wins because everything opens it. Keep JPG for e-mail, forms and WhatsApp; use WebP on websites.
When should I use PNG?
When the image has sharp edges and flat colours (logos, screenshots, diagrams, text) or needs a transparent background. For photos PNG is 3–8 times bigger than JPG with no visible benefit.
Do government portals accept WebP?
Mostly not. Indian government and exam portals ask for JPG or JPEG, sometimes PNG, with a size limit in KB. Convert to JPG before uploading.
What is AVIF?
A newer format that compresses even better than WebP (often 50% smaller than JPG). All current browsers show it; many apps and older phones do not. Good for your own website, not for sending to people.