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JPG to PNG

Process images in your browser — your files never leave your device.

Image ToolsFreeRuns in your browser
Interactive jpg to pngRuns in your browser, nothing uploadedFree, no account
Overview

What is the JPG to PNG?

This tool converts JPG files to PNG by decoding each JPEG onto a canvas and re-encoding it losslessly — no quality slider, because PNG has none to offer. Drop in one or more .jpg files and download pixel-identical PNGs at the same dimensions. The counterintuitive part: the output is almost always bigger than the input, often 2–4× bigger, because PNG has to losslessly store every JPEG compression artefact that already exists in the source, and that noisy detail compresses far worse than a clean photo would. This conversion exists for compatibility and lossless-editing reasons, not for saving space.

Convert JPG to PNG when a tool or workflow requires PNG input regardless of size — some design software, certain upload forms, or a pipeline that needs to add transparency to the image afterward. If your only goal is a smaller file, converting in this direction is the wrong move; PNG to JPG goes the other way for that.

Benefits

Why use a free jpg to png?

Genuinely lossless output

Once converted, the PNG can be edited, cropped or layered without introducing any new compression artefacts — useful as a base file for further lossless work.

Adds a real alpha channel

The output PNG supports transparency going forward, even though the source JPEG never could — useful as a first step before removing a background or compositing.

No quality setting to worry about

Because PNG is lossless, there is nothing to tune. The conversion either runs or it doesn't — there is no quality/size trade-off decision to make.

Universal PNG compatibility

PNG is accepted everywhere JPEG is, plus some places JPEG is not — certain design tools and print workflows require PNG or TIFF input specifically.

Batch conversion with ZIP download

Convert a whole folder of JPGs at once and get every PNG back in a single ZIP file.

Guide

How do you use the JPG to PNG?

  1. 1

    Add your JPG files

    Drag and drop one or more .jpg/.jpeg files, or click to browse.

  2. 2

    Convert

    There is no quality setting to configure — click Convert and each file is decoded and re-encoded as lossless PNG immediately.

  3. 3

    Check the size change

    Expect the PNG to be larger than the source JPG, sometimes significantly. This is normal and expected, not a sign of an error.

  4. 4

    Download

    Download files individually or as a ZIP for batches of more than one converted file.

Formula

How is jpg to png calculated?

Output size ≈ g(pixel count, image entropy) — always ≥ what a fresh lossless encode of the same pixels would need

Where:

pixel count
Width × height, unchanged by conversion
image entropy
How unpredictable the pixel values are — JPEG compression artefacts add fine, high-frequency noise that raises this and hurts PNG's compression ratio
DEFLATE ratio
PNG's lossless compressor works best on smooth, repetitive pixel data — the opposite of what heavily JPEG-compressed detail looks like

The simple version

PNG compresses by finding predictable patterns in pixel data and storing them more compactly. A clean, uncompressed photo has some of that predictability. A JPEG has already been through lossy compression, which leaves behind small blocky and ringing artefacts that look almost like noise to a lossless compressor — and noise is exactly what DEFLATE cannot compress well. That is why converting JPG to PNG usually grows the file instead of shrinking it.

Examples

What does it look like in practice?

Typical photo conversion

Input

1.2 MB JPEG photo, 3000×2000, quality unknown (as originally saved)

Result

~3.6 MB PNG

A 3× size increase is typical — the PNG has to losslessly encode every JPEG artefact already baked into the source pixels.

Simple graphic saved as JPEG by mistake

Input

180 KB JPEG of a flat-colour logo with sharp edges

Result

~95 KB PNG

One of the few cases where JPG to PNG produces a smaller file — flat colour and sharp edges compress well under PNG's lossless algorithm, and JPEG compression on this kind of content already introduces ringing artefacts that add file weight without adding real detail.

High-detail nature photo

Input

4.5 MB JPEG, 4032×3024, dense foliage and texture

Result

~14 MB PNG

Fine, high-frequency detail is the worst case for this conversion — both the real texture and the JPEG compression noise around it resist lossless compression.

Accuracy

How accurate is it?

The JPEG is decoded to a full bitmap using the browser's native decoder, then re-encoded with PNG's lossless DEFLATE compression via canvas.toBlob. The result is bit-for-bit identical to the decoded JPEG pixels — no further quality loss occurs during this conversion, only during the original JPEG encode that already happened before you uploaded it.

  • The output file size cannot be predicted from the input JPEG's size alone — it depends on how much detail and JPEG artefacting are present in the decoded pixels, which is why results vary by 2–4× larger even for similarly sized source files.
  • This conversion cannot undo JPEG compression artefacts — blocking or ringing already in the JPEG carries straight through to the PNG, just stored losslessly instead of further compressed.
  • A newly added alpha channel is fully opaque everywhere; JPG to PNG does not create transparency, it only makes the format capable of holding it for future edits.
Details

What should you know before using it?

What changes and what stays the same when converting JPG to PNG:

PropertyResult of conversion
File sizeTypically 2–4× larger, sometimes more for high-detail photos.
Image qualityUnchanged — the JPEG pixels are copied exactly, artefacts and all.
TransparencyAdded as a capability (fully opaque), not populated from anything in the source.
Pixel dimensionsUnchanged.
EditabilityImproved — the PNG can now be edited losslessly without stacking further compression artefacts.
Applications

When should you use a jpg to png?

Because the jpg to png runs entirely in your browser, it suits work you would not want to hand to a third-party server — client files, unpublished drafts, anything under an NDA. These are the situations people reach for it in most often.

Preparing a base file for background removal

Some background-removal and compositing tools expect or work more predictably with PNG input, since the output needs an alpha channel that JPEG cannot hold.

Design software requiring PNG import

Certain design and print tools restrict imports to lossless formats. Converting a JPEG asset to PNG satisfies that requirement without altering the visible image.

Avoiding generation loss during multi-step edits

If a JPEG is going to be cropped, layered or edited repeatedly, converting to PNG first stops each edit from re-compressing and degrading the image further.

Icon and asset pipelines that assume PNG

Build tools and app icon generators frequently only accept PNG source files — converting a JPEG source satisfies that even if the visual content started life as a photo.

Open the Icon and asset pipelines that assume PNG
FAQs

Frequently asked questions

Why does converting JPG to PNG make the file bigger?
Because PNG is lossless and has to store every pixel exactly, including the small compression artefacts already present in the JPEG. Those artefacts look like fine noise to PNG's compressor, which compresses poorly — so the lossless encode of an already-lossy image is usually 2–4× larger than the JPEG it came from.
Does converting JPG to PNG improve image quality?
No. The pixels are copied exactly as the JPEG decoder produced them — no detail is added back and no artefacts are removed. PNG simply stores those same pixels without any further loss during this specific conversion.
Can I add transparency to a JPG by converting it to PNG?
Converting alone does not add transparency — it only makes the file capable of holding an alpha channel, which starts fully opaque. To actually make part of the image transparent, you need a background-removal or manual editing step afterward.
Why would I convert JPG to PNG if the file gets bigger?
For lossless editing and format compatibility, not for smaller size. A PNG can be cropped, layered or resaved repeatedly without accumulating new compression artefacts, and some software and pipelines require PNG input regardless of the file size trade-off.
Is the conversion from JPG to PNG lossless?
The conversion step itself is lossless — every pixel the JPEG decoder produces is preserved exactly in the PNG. What's not undone is the lossy compression the JPEG already went through before you had it; PNG cannot recover detail a JPEG encoder already discarded.
Can I convert several JPG files to PNG at once?
Yes. Add multiple files, click Convert, and download the results either one at a time or all together as a ZIP file once the batch finishes.
Security

Is the jpg to png safe to use?

This tool runs entirely inside your browser. Your text, files and settings are processed on your own device and are never uploaded to our servers — there is nothing for us to store, log or leak. You can confirm it yourself: open your browser DevTools, switch to the Network tab, and use the tool. You will not see an upload request. It also means the tool keeps working if your connection drops mid-task.

No account required No file storage HTTPS everywhere
Sources

Where do these figures come from?

Every method, threshold and standard this page relies on, with a link to the document that defines it. Check them — a tool that will not show its sources is asking you to take its word for it.

  1. 1
    Portable Network Graphics (PNG) Specification (Third Edition)

    W3C · 2003

    Supports: The lossless DEFLATE re-encoding described, and why it stores JPEG artefact noise inefficiently.

  2. 2
    Information technology — Digital compression and coding of continuous-tone still images: Requirements and guidelines

    ITU-T Recommendation T.81 / ISO/IEC 10918-1 · 1992

    Supports: The description of the lossy DCT compression already applied to the source JPEG before this conversion runs.

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