User Guide
- Upload your image or drag & drop it into the tool above.
- Adjust the settings to get exactly the output you need.
- Preview and download your result in seconds.
About the PNG to JPG Converter
This tool converts a PNG image into JPG format in your browser. It is the conversion people reach for when a PNG is too large to email, too heavy for a web page, or rejected by a form that only accepts JPEG — and it works well for exactly those cases. But two things happen during the conversion that catch people out: transparency is destroyed, and the compression is permanent. Both are explained below so you can decide before you convert rather than afterwards.
What actually changes
PNG stores an exact copy of every pixel using lossless DEFLATE compression. JPEG throws information away deliberately — it transforms the image into frequency components and discards the ones your eye is least sensitive to. That is why the JPG is dramatically smaller, and why the discarded detail cannot be recovered by converting back.
The size reduction is usually substantial. A 12-megapixel photograph stored as a 20 MB PNG commonly converts to a 2–3 MB JPG at quality 85 with no difference visible at normal viewing distance. For photographic content this is one of the most effective size reductions available.
The transparency problem
JPEG has no alpha channel. None. When a PNG with a transparent background is converted, those transparent pixels must become something — and by convention that something is solid white or solid black, depending on the encoder.
This is the single most common surprise with this conversion. A logo that sat cleanly on any background as a PNG arrives as a rectangle with a white box around it. If your image relies on transparency, converting to JPG is the wrong operation. Keep the PNG, or convert to WebP, which supports both an alpha channel and lossy compression.
When PNG to JPG is the right conversion
| Situation | Convert? | Why |
|---|---|---|
| Photograph, no transparency | Yes | Large size saving, no visible loss |
| Screenshot with fine text | Usually not | JPEG blurs sharp edges and adds halos |
| Logo or icon with transparency | No | Transparency becomes a white box |
| Upload form that rejects PNG | Yes | Often the only option available |
| Image to be edited further | No | Each re-save loses more detail |
| Chart or diagram, flat colours | No | PNG is usually smaller and cleaner |
Understanding JPEG quality settings
JPEG quality is a scale, not a switch, and the relationship between the number and the file size is steeply non-linear. Moving from quality 100 to quality 90 typically removes more than half the file size while remaining visually indistinguishable, because quality 100 spends enormous space encoding detail nobody can see. Below about 70, blocking artefacts start becoming visible in smooth gradients — skies and skin tones show it first.
For most purposes quality 80–85 is the practical sweet spot: small files, no visible artefacts on typical content. If you need to hit a specific file size rather than a quality level — for an exam portal or a visa application — use the Image Compressor, which lets you work to a target instead.
Why re-saving a JPG repeatedly is a bad idea
Each JPEG save is a fresh round of lossy compression applied to whatever the previous save produced. Convert a PNG to JPG, open it, crop it, save it again, and you have compressed twice. Do it several times and the degradation becomes obvious — this is the well-known generation loss that makes images passed around messaging apps look progressively worse. If a file needs further editing, keep the PNG as your working master and export a JPG only at the end.
Worked example
A 3000×2000 pixel product photograph exported from a camera as PNG occupies 14.2 MB. Converted at quality 85 it becomes roughly 1.1 MB — a 92% reduction with no difference visible on screen. The same photo at quality 60 falls to about 480 KB, but gradients in the background begin to band. Converted to WebP at equivalent visual quality it lands smaller still; Google’s published comparison puts WebP lossy files 25–34% below JPEG at matched SSIM quality.
Privacy
The conversion runs entirely in your browser through the Canvas API. Nothing is uploaded, so there is no server copy of your image at any point. The tool continues to work with the network disconnected once the page has loaded.
Sources & further reading
- MDN — Image file type and format guide — covers JPEG’s lack of alpha support and the artefact behaviour described here.
- ITU-T T.81 — the JPEG standard — the original specification defining the DCT-based compression.
- Google — WebP comparison study — source of the 25–34% figure.
Frequently Asked Questions
Why did my transparent background turn white?
Because JPEG has no transparency support at all. Every pixel must have a colour, so transparent areas are filled — usually with white. This is not a fault in the converter; it is a limitation of the format. If you need transparency, keep the PNG or convert to WebP instead.
How much smaller will my file be?
For photographs, typically 80–95% smaller. A 14 MB PNG photo commonly becomes around 1 MB as a quality-85 JPG. For screenshots and flat graphics the saving is much smaller and sometimes negative — PNG can beat JPG on that kind of content.
Will I lose image quality?
Some, by definition — JPEG is lossy. At quality 80–85 the loss is not visible on typical photographic content at normal viewing sizes. It becomes visible on sharp text, hard edges and smooth gradients, which is why screenshots are better left as PNG.
Can I convert back to PNG afterwards?
You can, but it will not restore anything. The detail discarded during JPEG compression is gone; converting back simply wraps the degraded image in a lossless container. Always keep the original PNG if you may need it later.
What JPEG quality should I choose?
Around 80–85 for general use. Above 90 you pay a large size penalty for detail nobody can see; below 70 blocking artefacts start showing in skies and skin tones. If you need to hit an exact file size, use our Image Compressor instead.
Is JPG or PNG better for my website?
Photographs: JPG or WebP. Screenshots, logos, diagrams and anything with transparency: PNG or WebP. Using PNG for photographs is the most common cause of unnecessarily heavy pages.
Does my image get uploaded anywhere?
No. Conversion happens in your browser via the Canvas API. The file never leaves your device, and the tool works offline once the page has loaded.