JPEG vs PNG vs WebP vs SVG: Which Image Format to Use

What each image format is actually for, why JPG and JPEG are the same thing, when transparency forces your hand, and the one conversion that quietly ruins pictures.

Use JPEG for photographs, PNG when you need transparency or crisp text, WebP for anything going on a website, and SVG for logos and icons. That single sentence covers almost every decision anybody has to make about image formats.

The rest of this is why, and the handful of cases where following it blindly costs you something.

What is the difference between JPEG and PNG?

JPEG throws away detail to make the file small. PNG keeps every pixel exactly and accepts a larger file for it.

That difference decides everything else about them:

• JPEG is lossy. It discards information the eye is bad at noticing — mostly fine colour variation — and can make a photograph a tenth of the size with no visible difference. It cannot store transparency, and it smears sharp edges, which is why text and line art look muddy in it.
• PNG is lossless. Every pixel comes back exactly as it went in, it supports full transparency, and it stays crisp on hard edges. On a photograph it is often five to ten times larger than a JPEG that looks identical.

So the rule is about content, not quality: photographs are JPEG, and anything with transparency, flat colour or text in it is PNG. A screenshot of a spreadsheet belongs in PNG. A picture of a beach belongs in JPEG.

Is there any difference between JPG and JPEG?

No. They are the same format and the same file. The two extensions exist because older versions of Windows only allowed three characters after the dot, so .jpeg was written .jpg, and both survived.

Renaming a file from one to the other changes nothing about its contents. If a system insists on one of them, rename it freely.

What is WebP?

WebP is an image format Google released in 2010 that does both jobs: it can be lossy like JPEG or lossless like PNG, it supports transparency either way, and it produces smaller files than both at the same visible quality.

It is supported by every current browser, which is why sites serve it. Two things to know:

• It is a web format, not an everywhere format. Plenty of desktop software, print workflows and upload forms still will not take it, which is why "webp to jpg" is one of the most searched conversions there is.
• A WebP downloaded from a website is often already compressed. Converting it back to JPEG will not restore what the site removed.

What about AVIF?

AVIF is newer and usually smaller than WebP at the same quality, especially on photographs. It is supported by current browsers and less widely supported outside them.

If you are choosing today for a website, WebP is the safe default and AVIF is the smaller one. For anything leaving the web, JPEG or PNG.

SVG vs PNG: when do you need a vector?

Use SVG when the image is drawn rather than photographed — a logo, an icon, a chart. Use PNG when it is a picture of something, or when you need one fixed rendering.

The difference is that an SVG is instructions, not pixels. It says "a circle here, this path there", so it is perfectly sharp at any size: the same file works as a favicon and on the side of a van. A PNG is a fixed grid of pixels and gets soft when enlarged.

Two caveats worth knowing. An SVG can contain scripts, so many platforms refuse to accept one — that is a security decision, not a snub. And an SVG of a photograph is not a thing: tracing a photo into vectors makes a poster effect, not a smaller photo.

Which format should I use?

By what you are actually doing:

• Photograph for a website — WebP, or JPEG if anything in the chain refuses WebP.
• Photograph to email or print — JPEG.
• Logo or icon — SVG. PNG where SVG is not accepted.
• Screenshot — PNG. Text stays readable; JPEG will fur the edges of every letter.
• Anything needing a transparent background — PNG, WebP or SVG. Never JPEG.
• Animation — WebP or an actual video file. GIF is enormous by comparison and limited to 256 colours.
• Favicon — ICO or PNG, depending on what the platform asks for.
• Upload form with a size limit — JPEG, after resizing. See compressing an image to a size limit.

Why did my transparent background turn black when I converted to JPEG?

Because JPEG cannot store transparency, so the transparent pixels have to become some colour, and different tools choose differently. Some fill white, some fill black.

There is no setting that fixes this in JPEG, because the format has nowhere to record "this pixel is see-through". If you need the background gone, the output has to be PNG, WebP or SVG. If you are converting to JPEG deliberately, flatten the image onto the colour you want first, so the choice is yours rather than the converter's.

Does converting between formats lose quality?

Converting to a lossless format never loses anything. Converting to a lossy format always does, even if you cannot see it — and doing that repeatedly is where real damage happens.

This is called generation loss. A JPEG opened, edited and saved as a JPEG again has been through the discarding step twice. Do that a few times and you get the blocky, smeared look of an image that has been round the internet. The rules that follow from it:

• Keep an original in a lossless format if you will edit it again.
• Convert from the original each time, not from the last export.
• Converting a JPEG to PNG does not restore anything. It makes a large file that faithfully preserves the damage.

Lonecto's image converter handles JPEG, PNG, WebP, AVIF, GIF, BMP, TIFF and ICO, in the browser — the file never leaves your device, which for a folder of client photographs is the whole point. If the problem is size rather than format, the compressor is the other half.

Questions

Which is better, JPEG or PNG? Neither. They are for different content: JPEG for photographs, PNG for transparency, text and flat colour. Using the wrong one costs you either file size or visible quality.

Is WebP better than JPEG? Smaller at the same visible quality, and it supports transparency. Not better if the file has to be opened by something that does not read WebP.

Why is my PNG so large? Because it is lossless and probably a photograph. PNG stores every pixel exactly, and photographs have millions of slightly different ones. Save it as JPEG or WebP instead.

Can I convert a JPEG to SVG? Not meaningfully. Tracing a photograph produces a poster-like approximation, not a scalable version of the photo. SVG is for artwork that was drawn.

What image format is best for printing? Whatever your printer asks for, and at their requested resolution. Where there is no instruction, a high-quality JPEG or a TIFF. Not WebP.

Does renaming a .webp to .jpg convert it? No. The extension is a label; the contents are still WebP, and anything strict about formats will reject it. It has to be re-encoded.