Compress Images in Bulk for Free: BMP Files Shrank by 98%
Free Tool Tests โข Compress Images in Bulk for Free: BMP Files Shrank by 98%
๐ก Summary
You can compress images directly in your browser without uploading files to a server. In our desktop Chromium tests on November 7, 2026, all 19 test cases passed across formats like JPG, PNG, WebP, and BMP. Typical images shrank by 44 percent, while BMP files saw reductions of 98 percent.
Key Metrics & Specifications
| Tool | Free Image Compressor: Shrink JPG, PNG and WebP in Bulk |
| Tested | 2026-11-07 ยท Chromium (desktop) ยท free version |
| Test cases passed | 19 of 19 |
| Tool page | https://avaloncompany.ai/tools/compress-image/ |
What we ran through the tool
19 of 19 cases behaved correctly ยท 2026-11-07 ยท Chromium (desktop) ยท free version
| Input | Type | What the tool did |
|---|---|---|
| a typical file | Typical file | JPG file โ1 converted ยท 38.2 KB โ 21.3 KB (44% smaller)โ |
| a BMP image | Tricky file | JPG file โ1 converted ยท 351.6 KB โ 6.5 KB (98% smaller)โ |
| an animated GIF | Tricky file | JPG file โ1 converted ยท 4.2 KB โ 1.5 KB (65% smaller)โ |
| an iPhone HEIC photo | Tricky file | JPG file โ1 converted ยท 15.8 KB โ 22.1 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 | JPG file โ1 converted ยท 64.5 KB โ 15.1 KB (77% smaller)โ |
| a photo rotated by EXIF data | Tricky file | JPG file โ1 converted ยท 31.4 KB โ 19.0 KB (40% smaller)โ |
| a cut-off (truncated) JPEG file | Tricky file | JPG file โ1 converted ยท 12.7 KB โ 13.2 KBโ |
| a very long file name | Tricky file | JPG file โ1 converted ยท 38.2 KB โ 21.3 KB (44% smaller)โ |
| a file name with extra spaces and an emoji | Tricky file | JPG file โ1 converted ยท 38.2 KB โ 21.3 KB (44% smaller)โ |
| a file name with Korean and Japanese characters | Tricky file | JPG file โ1 converted ยท 38.2 KB โ 21.3 KB (44% smaller)โ |
| 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 | WEBP file โ1 converted ยท 7.2 KB โ 6.3 KB (12% smaller)โ |
| 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 Compress Images Step by Step
Drop your images into the tool. You can add up to 30 images in one batch on the free tier.
Choose your settings. Setting Quality to 72 percent is a good starting point. You can also define a Max width, such as 1,200 or 1,600 pixels, or change the format under Convert to. With Same as original selected, JPG stays JPG, PNG stays PNG, and WebP stays WebP. iPhone HEIC, GIF, and BMP files convert to JPG.
Press Compress images. Each image displays its new file size in the list. You can download images one by one or all at once, with no watermark and no account sign-up.
How We Tested the Image Compressor
We tested the free tier on November 7, 2026, using desktop Chromium. We evaluated 19 distinct test cases to verify standard operations and edge cases.
Our test set covered standard files, high-resolution photos, altered color spaces, rotated files, non-Latin filenames, truncated data, and batch limits. All 19 tests passed.
What Happened With Unusual and Edge-Case Files
BMP files saw the highest compression, dropping from 351.6 KB to 6.5 KB (98% smaller). An animated GIF shrank from 4.2 KB to 1.5 KB (65% smaller), and a CMYK JPEG shrank from 64.5 KB to 15.1 KB (77% smaller). An 8000 ร 6000 px image decreased from 1.43 MB to 1020.7 KB (30% smaller).
Special characters in file names caused no issues. Files with long names, extra spaces, emojis, and Korean or Japanese text all converted normally, reducing from 38.2 KB to 21.3 KB (44% smaller). An EXIF-rotated photo shrank from 31.4 KB to 19.0 KB (40% smaller).
Some files did not reduce in size. A transparent PNG stayed at 2.6 KB, a 16-bit PNG stayed at 3.8 KB, and a 1 ร 1 px image stayed at 69 B because PNG compression is lossless. An iPhone HEIC photo went from 15.8 KB to 22.1 KB, and a cut-off JPEG went from 12.7 KB to 13.2 KB.
Corrupt or non-image files were rejected cleanly. Both an empty 0-byte file and a renamed PDF showed the error message: "This file could not be read as an image."
Free Tier Limits and When to Consider Other Options
The free tool allows up to 30 files per batch. Adding 31 files triggers the message: "Only 30 images fit in one batch, so 1 more was not added. Convert these first, then add the rest."
PNG files do not shrink with the Quality slider because PNG retains full detail. If you want a smaller file from a PNG photo or screenshot, choose JPG or WebP under Convert to.
The free tier does not include ZIP downloads, saved presets, custom file names, or batches larger than 30 images. Those features require 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 anywhere?
No. The images are compressed inside your browser, on your own device. Nothing is sent to our servers.
Q. Why did my PNG file not get smaller?
PNG is saved without losing detail, so the quality slider does not change it. If a compressed copy would be larger, the original is kept. For photos and screenshots, choose WebP or JPG under Convert to: they are usually much smaller.
Q. How do I get an image under a size limit, such as 1 MB?
Lower the Quality, set a Max width (1,600 or 1,200 pixels is plenty for most forms and websites), or both. The new size is shown next to each image, so you can adjust and try again.
Try it on your own file
The same free tool we tested above. No sign-up.
Internal link to avaloncompany.ai.