How to convert an image between JPG, PNG, WebP and AVIF
Open the image in a converter, pick the format you want, and download the result. Photographs belong in JPG or WebP; screenshots, logos, diagrams and anything needing transparency belong in PNG. Converting is one-way for quality: turning a JPG into a PNG cannot bring back detail the JPG already threw away.
An image file is two things: a grid of coloured dots, and a set of rules for writing that grid down without using an absurd amount of space. The format is the rulebook. Converting means unpacking the picture with one rulebook and repacking it with another. That is why some conversions cost you nothing and others quietly cost you detail you can never get back.
The four formats you will actually meet
| Format | Compression | Transparency | Use it for |
|---|---|---|---|
| JPG (also written JPEG) | Lossy: it discards detail to save space, and you choose how much | No | Photographs, and anything else made of soft gradients rather than hard edges |
| PNG | Lossless: every pixel comes back exactly as it went in | Yes | Screenshots, logos, diagrams, line art, and anything that needs a see-through background |
| WebP | Either, your choice per file | Yes | Web images generally. Roughly 25 to 35 percent smaller than JPG at the same visual quality |
| AVIF | Either, your choice per file | Yes | The smallest of the four at a given quality, often around half the size of the equivalent JPG |
The one rule that covers most decisions: photographs go to JPG or WebP, anything with flat colour, sharp text or transparency goes to PNG. A holiday photo saved as PNG is typically five to ten times larger than the JPG for no visible gain. A screenshot of a spreadsheet saved as JPG comes back with faint smeared halos around every letter and number, because JPG was designed for skin tones and skies, not for a hard black line meeting a white background.
Converting, step by step
- Open the converterGo to image converter and drop the picture in. The file is decoded in the tab you are looking at. Nothing is uploaded, no account is needed, and there is no monthly allowance to run down.
- Pick the output formatChoose the target from the list. If a website or a form told you what it accepts, use exactly that. Forms that say "JPG only" usually mean it, and renaming a
.pngfile to.jpgdoes not convert anything: the contents are still PNG and the upload will be rejected. - Set the quality, if the target is lossyJPG, WebP and AVIF all take a quality number. 80 is a sensible default for photographs. PNG has no quality setting, because it never throws anything away.
- Check the size before you commitThe output size is shown next to the preview. If a 4 MB photograph converts to a 30 KB JPG, the quality is set far too low; if it converts to 6 MB, you have probably picked PNG by mistake.
- Download and renameThe converted file downloads with the new extension. Rename it now if it is going somewhere fussy, because
IMG_4471 (2).jpgis not a filename anybody wants attached to an insurance claim.
Convert between JPG, PNG, WebP and AVIF in your browser. The picture never leaves your computer.
Image Converter →Converting a JPG to PNG does not improve it
This is the single thing most people get wrong. PNG is lossless, so the conversion is faithful, but it is faithful to the JPG, blur and blocks and all. The detail JPG discarded when the photo was first saved is gone from the file. PNG has nothing to reconstruct it from, so all you get is a much larger file containing exactly the same damage.
The same logic applies to quality numbers. Re-saving a quality 60 JPG at quality 95 does not restore anything either. It just stores the already-degraded picture more carefully. If you need a better version, you need the original: the camera file, the design file, or the person who sent it. There is no software anywhere that recovers detail a lossy format has already thrown away, however confidently it claims otherwise.
Converting the other way, PNG to JPG, is a real loss and happens the moment you press convert. Keep the PNG. If the JPG turns out to be too soft or the wrong size, you want the untouched original to try again from.
Transparency, and what JPG does to it
PNG, WebP and AVIF can store a transparent background: a logo with nothing behind it, a signature with no white box around it, an icon that sits on any colour. JPG cannot. It has no way to record "nothing here", so a converter has to fill those pixels with something, normally white or black.
That is how a transparent logo ends up as a white rectangle on a dark website header. If your image has transparency you care about, your options are PNG, WebP or AVIF, and there is no clever setting that makes JPG behave. If you are pulling a transparent graphic out of a document, PDF to PNG with transparency covers that route.
HEIC, the format your iPhone hands you
Photographs taken on a recent iPhone are saved as HEIC by default, which is about half the size of JPG at the same quality but is refused by a great many websites, printers and older Windows machines. Converting HEIC to JPG is the fix, and it is the most common image conversion people ever do.
- Stop it happening again: on the iPhone, Settings, Camera, Formats, choose Most Compatible. New photos are then JPG. Existing ones stay HEIC.
- Convert what you already have: run the file through a converter and choose JPG. Quality 85 keeps the difference invisible.
- Emailing or AirDropping first: sending a HEIC photo to a Windows PC via most mail apps converts it to JPG on the way, which is sometimes all you need.
Which format if it is going on paper
Print does not care about WebP or AVIF, and many print shops will not accept either. For anything printed, use JPG at high quality or PNG, and worry about the pixel dimensions rather than the format: an image needs roughly 300 dots per inch at its printed size, so a photo filling a 6 by 4 inch print wants around 1800 by 1200 pixels. Choosing an image format for print works through the arithmetic properly.
Once the format is right, the next question is usually size. If the file is still too heavy for an upload limit, compressing the image is the next step, and if you are collecting several pictures to send as one document, turn them into a PDF instead of attaching eleven separate files.
Frequently asked questions
Does converting a JPG to PNG improve the quality?
No. PNG stores the JPG faithfully, including every bit of blur and blocking the JPG already had. The detail JPG discarded is not in the file any more, so nothing can bring it back. You just get a much bigger file with the same flaws.
Should I use JPG or PNG?
Photographs to JPG, everything with flat colour, sharp text or transparency to PNG. A screenshot saved as JPG gets smeared halos around the text; a photograph saved as PNG is five to ten times larger with no visible gain.
Is WebP better than JPG?
For anything shown on screen, usually yes. WebP is around 25 to 35 percent smaller at the same visual quality and it supports transparency, which JPG does not. For print or for a form that demands JPG, stick with JPG.
Can I just rename a .png file to .jpg?
No. The extension is only a label; the contents are still PNG. Some software will open it anyway, but strict uploads and print systems read the file itself and reject it. Convert properly instead, which takes a couple of seconds.
How do I convert an iPhone HEIC photo to JPG?
Run it through an image converter and choose JPG at quality 85. To stop it recurring, open Settings, Camera, Formats on the iPhone and pick Most Compatible so new photos are saved as JPG from the start.