Convert PNG images to JPG for smaller file sizes -- free, private, browser-based
Read more: PNG to JPG Converter
PNG is lossless but large. JPG trades a small amount of quality for dramatically smaller files -- often 60-80% smaller. If you do not need transparency or pixel-perfect reproduction, this conversion makes your images practical to share, upload, and store.
This is the single most important thing to understand about this conversion. JPG has no alpha channel. It cannot represent transparency at all. Every transparent pixel in your PNG will become solid white in the JPG output.
If your PNG is a logo on a transparent background, the JPG will be that logo on a white rectangle. If it is a product photo with the background removed, the cutout will sit on white. There is no setting to change this -- it is a fundamental limitation of the JPG format.
If you need to keep transparency and still want smaller files, convert to WebP instead. WebP supports alpha channels and still compresses significantly smaller than PNG.
Screenshots are the most common PNG files people want to shrink, and they respond well to JPG conversion -- but not all screenshots are equal.
UI screenshots (app interfaces, web pages, dashboards with gradients and photos) compress well at quality 85-90. The lossy artifacts blend into the visual complexity and are not noticeable at normal viewing size. Expect 80-90% file size reduction.
Code and terminal screenshots are trickier. Monospaced text on a solid background creates sharp, high-contrast edges -- exactly the kind of content where JPG artifacts show up most. Below quality 85, you may see ringing around letterforms and color fringing on syntax highlighting. Stick to 90 or above for these, or keep them as PNG if pixel-perfect text matters.
Mixed screenshots (a browser window showing both UI and text) do fine at 85. The text areas will soften very slightly, but not enough to affect readability in documentation or bug reports.
Quality 90-100: Near-lossless. Best for images you plan to edit further or that need high fidelity. File size savings compared to PNG are still significant.
Quality 80-90: The sweet spot. Compression artifacts are not visible at normal viewing distances. This is where most web images should land.
Quality 60-80: Good for thumbnails, previews, and images where small file size matters more than perfect quality. Artifacts become visible on close inspection.
Below 60: Noticeable quality loss. Only useful when extreme file size reduction is the priority.
One of the most common reasons to convert PNG to JPG is hitting an attachment or upload limit. Here is what the major platforms allow:
| Platform | Attachment Limit | Notes |
|---|---|---|
| Gmail | 25 MB total | Multiple attachments share the limit |
| Outlook | 20 MB | Some organizations set lower limits (10 MB) |
| Slack (free) | 25 MB per file | Pro plans vary |
| Discord | 8 MB (free), 50 MB (Nitro) | Per-file limit |
| LinkedIn messages | 20 MB | Per attachment |
| iMessage | 100 MB | Images auto-compressed by the system |
| 16 MB | Images auto-compressed on send |
A full-screen screenshot saved as PNG is typically 2-5 MB. Attach three or four to an email and you are already bumping against Gmail's limit. Converting those same screenshots to JPG at quality 85 can turn a 3 MB PNG into a 400 KB JPG -- making the difference between an email that sends and one that bounces.
If you have scanned a stack of documents -- say 50 pages of contracts, receipts, or forms -- and your scanner saved them as PNGs, you could be looking at several gigabytes of storage for what is essentially flat text on white paper. JPG at quality 85-90 handles scanned documents well, reducing each page from 5-10 MB down to 300-800 KB.
This tool processes one image at a time, which is fine for a handful of files. For bulk conversion, dedicated tools are faster:
mogrify -format jpg -quality 85 *.png converts every PNG in the current folderFor one-off conversions or a few files, this browser-based tool avoids installing anything. For hundreds of files, reach for the command line.
For UI screenshots with gradients and photos, quality 85 is a good default. For code or terminal screenshots with sharp text, bump it to 90. Below 85, text edges may show visible compression artifacts.
Yes. JPG compression is lossy -- it permanently discards some detail to achieve smaller file sizes. If you might need the full lossless quality later, keep the original PNG as your master file. You can always re-convert, but you cannot recover what JPG compression removes.
JPG does not support transparency. Every transparent pixel is filled with white during conversion. If you need to keep the transparent background, use PNG to WebP instead -- WebP supports transparency and still gives you smaller file sizes than PNG.
If you want to stay in PNG format but reduce size, try the Image Compressor which can optimize PNG files. But the savings are modest compared to switching to JPG. For maximum compression with good quality, WebP is the best option.