Is ToolFlow really free?

Yes. Every tool is completely free with no limits, sign-up or installation.

Many tools process files directly in your browser so data never leaves your device.

What happens to a transparent background when I convert PNG to JPG?

JPG does not support transparency, so transparent areas are filled with white in the result. If you need a different background colour, add it in an image editor before converting.

Will converting PNG to JPG make the file smaller?

Usually, yes, and often by a lot for photos, because JPG compresses photographs much more than PNG does. Flat graphics, logos and screenshots with sharp text do not always shrink as much.

Does converting JPG to PNG improve the quality?

No. A JPG has already lost some detail when it was first saved. Converting it to PNG makes a lossless copy of the image as it is now. It cannot bring back the detail that was lost, and the PNG file is often larger.

Why would I convert JPG to PNG at all?

Mainly to avoid losing more quality when you edit and save the image repeatedly, or because a tool or platform asks for PNG. It also lets you add transparency in an editor afterwards.

Is the conversion done on a server?

No. It runs in your browser using the Canvas API, so your image is not uploaded.

Which format should I use for a website?

Use JPG for photographs and PNG for logos, icons and graphics with sharp edges or transparency. The PNG vs JPG guide on this site goes into more detail.

How to Convert PNG to JPG and JPG to PNG

How to Convert PNG to JPG (and JPG to PNG) Without Surprises

Converting between PNG and JPG takes a few seconds, but it can quietly change your image: transparent areas turn white, and quality cannot be restored. Here is what really happens and how to choose.

By ToolFlow Team November 14, 2026 6 min read

Two formats cover most of the images you meet every day: PNG and JPG. Converting from one to the other is quick, but it is not neutral. Something changes in the image each time, and knowing what helps you avoid ruined logos, white boxes behind transparent graphics and files that come out bigger than they went in.

The one difference that matters

PNG saves every pixel exactly as it is and can store transparency. JPG throws away fine detail the eye is unlikely to notice in order to make the file much smaller, and it cannot store transparency at all. Everything else follows from that. PNG is exact and larger. JPG is smaller and slightly approximate.

How to convert PNG to JPG

Open the PNG to JPG converter.
Upload your PNG by clicking to browse or dragging it in.
Click Process.
Download the JPG.

The conversion happens in your browser using the Canvas API, so the image is not uploaded to a server.

What happens to transparent areas

This is the surprise that catches most people. JPG has no transparency, so any see-through area in your PNG is filled with white. A logo with a transparent background will come out as a logo on a white rectangle. That is fine if you are putting it on a white page, but it will look wrong on a coloured background. If you need a different colour behind it, add that colour in an editor first and then convert.

How to convert JPG to PNG

Open the JPG to PNG converter.
Upload your JPG.
Click Process.
Download the PNG.

What a JPG to PNG conversion cannot do

People often convert a JPG to PNG hoping to get a sharper picture. It does not work that way. The detail was lost when the JPG was first saved, and converting only copies what is left into a lossless format. The result looks the same, and the file is usually bigger. What you gain is protection from further loss: once the image is a PNG, you can edit and save it again and again without it getting worse each time.

The other useful reason is transparency. A PNG can have a see-through background, so converting to PNG is the first step before removing a background in an editor.

When to convert, and when to leave it alone

Convert PNG to JPG for finished photographs you want to upload, email or put on a website, where file size matters and you do not need transparency.
Do not convert PNG to JPG for logos, icons, line art or screenshots with small text. JPG tends to leave fuzzy marks around sharp edges.
Convert JPG to PNG when you plan to edit the image several times, or when a platform requires PNG.
Do not convert JPG to PNG just to improve quality, or to save space. It does neither.

Make the file smaller after converting

If a JPG is still too large to upload, the Image Compressor can shrink it further, and the Image Resizer can reduce its dimensions. Cutting the pixel size is often the biggest saving of all.

Common mistakes

Converting a logo to JPG and losing its transparency. Keep a PNG copy of any logo.
Converting back and forth. Each trip through JPG loses a little more detail. Keep your original file.
Expecting a smaller file from every conversion. Photos shrink a lot. Simple graphics may not.

Not sure which format you need? Our PNG vs JPG guide explains the choice in more depth.