Convert JPG to PNG Online: Why Typical Files Grow to 138.0 KB
Free Tool Tests โข Convert JPG to PNG Online: Why Typical Files Grow to 138.0 KB
๐ก Summary
Convert your JPG images to lossless PNG files directly in your web browser. In our desktop tests, all 19 test cases passed without sending any files to a remote server. You can convert up to 30 images per batch for free with no watermark.
Key Metrics & Specifications
| Tool | Free JPG to PNG Converter: Lossless PNG Files in Bulk |
| Tested | 2026-11-04 ยท Chromium (desktop) ยท free version |
| Test cases passed | 19 of 19 |
| Tool page | https://avaloncompany.ai/tools/jpg-to-png/ |
What we ran through the tool
19 of 19 cases behaved correctly ยท 2026-11-04 ยท Chromium (desktop) ยท free version
| Input | Type | What the tool did |
|---|---|---|
| a typical file | Typical file | PNG file โ1 converted ยท 38.2 KB โ 138.0 KBโ |
| a BMP image | Tricky file | PNG file โ1 converted ยท 351.6 KB โ 8.7 KB (98% smaller)โ |
| an animated GIF | Tricky file | PNG file โ1 converted ยท 4.2 KB โ 3.3 KB (21% smaller)โ |
| an iPhone HEIC photo | Tricky file | PNG file โ1 converted ยท 15.8 KB โ 103.0 KBโ |
| a PDF file renamed to look like an image | Tricky file | Not processed โThis file could not be read as an image.โ |
| an empty (0-byte) image file | Tricky file | Not processed โThis file could not be read as an image.โ |
| a CMYK JPEG | Tricky file | PNG file โ1 converted ยท 64.5 KB โ 72.6 KBโ |
| a photo rotated by EXIF data | Tricky file | PNG file โ1 converted ยท 31.4 KB โ 140.2 KBโ |
| a cut-off (truncated) JPEG file | Tricky file | PNG file โ1 converted ยท 12.7 KB โ 57.1 KBโ |
| a very long file name | Tricky file | PNG file โ1 converted ยท 38.2 KB โ 138.0 KBโ |
| a file name with extra spaces and an emoji | Tricky file | PNG file โ1 converted ยท 38.2 KB โ 138.0 KBโ |
| a file name with Korean and Japanese characters | Tricky file | PNG file โ1 converted ยท 38.2 KB โ 138.0 KBโ |
| a 16-bit PNG | Tricky file | PNG file โ1 converted ยท 3.8 KB โ 3.8 KBโ |
| a 1 ร 1 px image | Tricky file | PNG file โ1 converted ยท 69 B โ 69 Bโ |
| an 8000 ร 6000 px image | Tricky file | PNG file โ1 converted ยท 1.43 MB โ 1020.7 KB (30% smaller)โ |
| a transparent PNG | Tricky file | PNG file โ1 converted ยท 2.6 KB โ 2.6 KBโ |
| a WebP image | Tricky file | PNG file โ1 converted ยท 7.2 KB โ 64.4 KBโ |
| 30 files (exactly the free limit) | Free limit | Not processed โ30 images readyโ |
| 31 files (one over the free limit) | Free limit | Not processed โOnly 30 images fit in one batch, so 1 more was not added. Convert these first, then add the rest.โ |
โBehaved correctlyโ means the tool produced a valid output file we reopened and checked, or refused the input with a clear message. Open the tool.
Try it on your own file
The same free tool we tested above. No sign-up.
Internal link to avaloncompany.ai.
How to convert JPG to PNG step by step
Drop your JPG images into the tool area.
Leave the Convert to option set to PNG.
Press the Convert to PNG button to run the conversion.
Download your converted PNG files one by one or all at once.
You do not need to create an account, and your downloads will have no watermark.
How we tested the tool
We tested the free converter on 2026-11-04 using Chromium on a desktop computer.
We ran 19 separate test cases covering normal photos, unusual graphic formats, and batch boundaries.
All 19 tests passed successfully.
The tool performed all conversions inside the browser on the local device, sending no files to external servers.
Handling unusual and damaged files
The tool converted a wide variety of edge cases without errors.
A cut-off JPEG converted into a PNG, increasing from 12.7 KB to 57.1 KB.
An 8000 ร 6000 px photo converted without crashing, reducing from 1.43 MB to 1020.7 KB.
Files with Korean and Japanese characters, extra spaces, and emojis in their names converted smoothly.
When given a 0-byte file or a PDF renamed as an image, the tool refused both and showed the message: "This file could not be read as an image."
Free tier limits and when to use another tool
The free tier caps each batch at 30 images. When we uploaded 31 files, the tool warned: "Only 30 images fit in one batch, so 1 more was not added. Convert these first, then add the rest."
Converting to PNG does not add transparency to a solid background, and it cannot restore pixel detail lost during original JPG compression.
PNG files are often much larger than JPGs because they retain every pixel. In our baseline test, a 38.2 KB JPG expanded to 138.0 KB as a PNG.
If you need ZIP downloads, custom presets, or larger batch sizes, the free tier will require multiple runs or an upgrade to Avalon Pro.
We re-run these tests when the tool changes. Results describe this tool on the date shown.
Frequently Asked Questions (FAQ)
Q. Are my images uploaded to your servers?
No. The images are converted inside your browser, on your own device. Nothing is sent to our servers.
Q. Will converting to PNG make my photo sharper?
No. PNG stores the picture exactly as it is now, so it will not lose any more quality when you edit and save it again, but it cannot bring back detail the JPG already dropped.
Q. Does converting to PNG give me a transparent background?
Not by itself: the background of a photo stays as it is. To remove the background and get a transparent PNG, use our free background remover.
Try it on your own file
The same free tool we tested above. No sign-up.
Internal link to avaloncompany.ai.