Does converting JPG to PNG improve the quality?

No, and this is the most common misunderstanding about the conversion. PNG stores exactly what it is given, losslessly — but what it is given is the already-degraded output of JPG compression. You get a perfect copy of a lossy image, not a restored original. Compression artefacts are preserved with total fidelity.

Why is the PNG so much larger than the JPG?

On our fixed test image a 375 KB JPG became a 2.37 MB PNG, about six and a half times larger. JPG achieves its size by discarding fine detail; PNG has to store every remaining pixel exactly, including the subtle noise and artefacts JPG introduced. Those artefacts are high-frequency detail, which is precisely what lossless compression handles worst.

Can I get a transparent background this way?

Not automatically. PNG supports transparency and JPG does not, so the conversion gives you a PNG with a fully opaque background. Removing a background is an editing operation, not a format conversion, and it needs an image editor.

When is converting JPG to PNG actually the right move?

When a tool or platform demands PNG specifically; when you are about to edit the image and want no further generational loss from this point on; or when you need an alpha channel to add transparency yourself afterwards.

Is the PNG optimised?

Yes. Every PNG here is passed through oxipng, which rewrites the compression losslessly. The pixels are bit-for-bit identical to an unoptimised PNG; the file is simply smaller.

Is my image uploaded?

No. Both decoding and encoding happen in this browser tab, in a Web Worker. The Uploaded readout beside the result measures the page's own outbound traffic, so a successful conversion reads 0 B.

Is there a file size limit?

None imposed. There is no server and no bandwidth cost, so your device's memory is the only ceiling. Because PNG output is large, memory becomes the constraint sooner here than on other converters.

Can I convert many files at once?

Yes, but be modest with batch sizes. Each PNG is many times larger than its source, and holding several in memory at once adds up quickly on a phone.

Will there be a watermark?

No. Nothing is added and nothing is withheld behind a paid tier.

Does the PNG keep the photo's EXIF data?

Most metadata is not carried across. If the capture date or GPS coordinates matter, keep the original JPG — this tool never modifies your source file.

Should I use PNG or WebP for a website?

WebP, almost always. It supports transparency like PNG, compresses like JPG, and is supported by every current browser. PNG on a web page is usually a legacy choice rather than a deliberate one.

What is the difference between PNG and JPG?

JPG is lossy and designed for photographs: it discards detail your eye is unlikely to miss, achieving small files. PNG is lossless and designed for graphics: it stores every pixel exactly and supports transparency, at the cost of much larger files for photographic content.

Convert JPG to PNG

A lossless PNG copy of your JPG, made on your own machine. Nothing is uploaded, and there's no size limit.

ReadyJPG → PNG

Uploaded0 B

What next

How do I convert JPG to PNG?

To convert a JPG to PNG, drop the file onto this page and download the PNG it returns. The conversion runs in your browser and nothing is uploaded. PNG is lossless, so nothing further is discarded — but the file will be much larger, because PNG must store detail that JPG compression already threw away.

How to do it

Open the converter. Open this page in any modern browser. No installation, no account, no upload.
Add your JPG files. Drag them onto the panel or click to choose. Add as many as your device's memory will hold.
Let it encode. Each PNG is written losslessly and then optimised with oxipng, which shrinks the file without altering a single pixel.
Download the PNG. Every result gets its own link. Expect a much larger file than the JPG you started with — see the measured figures below.

At a glance

Converts	JPG to PNG
Transparency	Preserved
Compression	Lossless encode, but detail already lost by JPG cannot come back
Where it runs	In this browser tab. The file is not uploaded
File size limit	None imposed — your device memory is the ceiling
Cost	Free
Account needed	No
Watermark	None
Works offline	Usually after first use, but not guaranteed — there is no offline app

What it actually produces

Measured, not estimated. A procedurally generated 2400×1600 (3.8 MP) test image built to carry photographic entropy: value noise across nine octaves down to near-pixel scale, a dense field of small high-contrast features, a smooth gradient, hard edges and light grain. It is not a photograph — it is reproducible, which a photograph is not. Each figure below comes from running that image through this page.

Input	Output	Change
375 KB	2.37 MB	6.5× larger

Your own files will differ — a photograph, a screenshot and a diagram compress very differently. The point of a fixed image is that the formats can be compared with each other, not that your result will match.

Does converting JPG to PNG improve quality?

No. This is worth stating first because it is the assumption that brings most people to this page.

PNG is lossless, so it stores exactly what it is given. But what it is given here is the output of JPG compression — an image from which detail has already been permanently discarded. The PNG preserves that degraded image with complete fidelity, artefacts and all.

Converting JPG to PNG is a way to stop losing quality from this point forward. It is not a way to recover quality already lost.

Why is the PNG so much bigger?

Substantially bigger. On the fixed test image used for every measurement on this site, a 375 KB JPG became a 2.37 MB PNG — around six and a half times larger.

Two things drive that. First, JPG achieved its small size by discarding fine detail, and PNG has to store whatever remains exactly. Second, JPG compression introduces its own subtle noise, and noise is the single hardest thing for lossless compression to handle. The PNG ends up faithfully encoding the JPG’s artefacts.

Every PNG produced here is run through oxipng afterwards, which recovers some of that size losslessly — same pixels, smaller file — but it cannot change the fundamental arithmetic.

When is this conversion the right move?

There are three good reasons:

A tool or platform requires PNG. Some upload forms, icon pipelines and design tools accept nothing else.
You are about to edit the image. Working from PNG means repeated saves do not compound JPG’s generational loss.
You need an alpha channel. JPG cannot store transparency at all. Converting to PNG gives you a format that can, so you can cut out a background afterwards in an editor.

Note the third one carefully: the conversion gives you a PNG capable of transparency, with a fully opaque background. It does not remove anything.

What about PNG for the web?

Generally, don’t. WebP does everything PNG does on a web page — including transparency — at a fraction of the size, and every current browser supports it.

PNG on a modern web page is usually a legacy decision rather than a deliberate one.

Questions

Does converting JPG to PNG improve the quality?: No, and this is the most common misunderstanding about the conversion. PNG stores exactly what it is given, losslessly — but what it is given is the already-degraded output of JPG compression. You get a perfect copy of a lossy image, not a restored original. Compression artefacts are preserved with total fidelity.
Why is the PNG so much larger than the JPG?: On our fixed test image a 375 KB JPG became a 2.37 MB PNG, about six and a half times larger. JPG achieves its size by discarding fine detail; PNG has to store every remaining pixel exactly, including the subtle noise and artefacts JPG introduced. Those artefacts are high-frequency detail, which is precisely what lossless compression handles worst.
Can I get a transparent background this way?: Not automatically. PNG supports transparency and JPG does not, so the conversion gives you a PNG with a fully opaque background. Removing a background is an editing operation, not a format conversion, and it needs an image editor.
When is converting JPG to PNG actually the right move?: When a tool or platform demands PNG specifically; when you are about to edit the image and want no further generational loss from this point on; or when you need an alpha channel to add transparency yourself afterwards.
Is the PNG optimised?: Yes. Every PNG here is passed through oxipng, which rewrites the compression losslessly. The pixels are bit-for-bit identical to an unoptimised PNG; the file is simply smaller.
Is my image uploaded?: No. Both decoding and encoding happen in this browser tab, in a Web Worker. The Uploaded readout beside the result measures the page's own outbound traffic, so a successful conversion reads 0 B.
Is there a file size limit?: None imposed. There is no server and no bandwidth cost, so your device's memory is the only ceiling. Because PNG output is large, memory becomes the constraint sooner here than on other converters.
Can I convert many files at once?: Yes, but be modest with batch sizes. Each PNG is many times larger than its source, and holding several in memory at once adds up quickly on a phone.
Will there be a watermark?: No. Nothing is added and nothing is withheld behind a paid tier.
Does the PNG keep the photo's EXIF data?: Most metadata is not carried across. If the capture date or GPS coordinates matter, keep the original JPG — this tool never modifies your source file.
Should I use PNG or WebP for a website?: WebP, almost always. It supports transparency like PNG, compresses like JPG, and is supported by every current browser. PNG on a web page is usually a legacy choice rather than a deliberate one.
What is the difference between PNG and JPG?: JPG is lossy and designed for photographs: it discards detail your eye is unlikely to miss, achieving small files. PNG is lossless and designed for graphics: it stores every pixel exactly and supports transparency, at the cost of much larger files for photographic content.

About these formats

Sources

Portable Network Graphics (PNG) Specification, Third Edition — W3C
ITU-T T.81 — the JPEG specification — ITU-T
oxipng, the lossless PNG optimiser used here — oxipng contributors