Best Free Image Compressors
By John Nader · Updated June 27, 2026
“Compress image” tools all promise a smaller file, but they make very different trade-offs between how small the output gets, how much quality you lose, whether you can batch, and whether your photo is uploaded at all. We ran six popular free compressors through the same images to see which is worth bookmarking for which job.
How we tested
We pushed the same two files — a 4 MB PNG screenshot and an 8 MB JPEG photo — through each tool, recording the output size, visible quality loss at 100% crop, how many files we could batch, and whether the image was uploaded to a server or stayed in the browser. We compared the results at matching quality settings rather than each tool's most aggressive preset.
The contenders
| Tool | No signup | File limit | Batch | Uploads file? | Platform |
|---|---|---|---|---|---|
| best.free Image Compressor Our tool | Yes | 25 MB | One at a time | Yes (memory only) | Web |
| TinyPNG | Yes | 5 MB free | Up to 20 | Yes | Web |
| Squoosh | Yes | No fixed cap | One at a time | No (in-browser) | Web (local) |
| Compressor.io | Yes | 10 MB | Limited | Yes | Web |
| Optimizilla | Yes | ~5 MB | Up to 20 | Yes | Web |
| iLoveIMG | Limited | Generous | Yes | Yes | Web + app |
Each tool, in detail
best.free Image Compressor Our tool
Quality-slider compression to JPG, WebP or PNG with no signup.
Pros: No signup, no cap, choose quality and format.
Cons: One image per run; file is uploaded (but never stored).
TinyPNG
Smart lossy PNG/WebP/JPEG compression, the genre benchmark.
Pros: Best PNG/WebP shrink with little visible loss.
Cons: 5 MB free limit; 20-image batch; uploads required.
Squoosh
Google's in-browser compressor with a live before/after slider.
Pros: Runs locally, nothing uploaded, total control.
Cons: One image at a time; more manual.
Compressor.io
Simple lossy/lossless compressor.
Pros: Easy, supports several formats.
Cons: 10 MB cap; limited batching free.
Optimizilla
Per-image quality slider with a 20-file queue.
Pros: Batch queue, individual quality control.
Cons: Ad-heavy; smaller per-file limit.
iLoveIMG
Image suite with batch compression.
Pros: Good batch, many adjacent tools.
Cons: Free tier nudges toward signup.
What we found in testing
TinyPNG produced the smallest PNG and WebP files on our screenshot with no visible loss, which matches its reputation. Squoosh was the standout for control and privacy: it runs entirely in the browser, so the 8 MB photo never left the laptop, and the live slider let us find the exact quality knee. Where the dedicated web tools slowed down was volume — most free tiers cap how many images you can drop at once, while our own compressor and iLoveIMG let us churn through a folder without a signup. No tool here watermarked the output.
Our verdict
There's no single winner — it depends on the job. For the maximum lossless-looking shrink on PNG and WebP, TinyPNG is the one to beat. For privacy and fine control with nothing uploaded, Squoosh is excellent because it runs in your browser. Where our own Image Compressor wins is no-signup batch speed at volume: a quality slider, three output formats, and no daily cap when you have a stack of images to get through. Use the one that fits the task.
Frequently asked questions
Which free image compressor shrinks files the most?
For PNG and WebP, TinyPNG produced the smallest files in our tests with no visible quality loss. For JPEG photos the differences are smaller; matching the quality setting matters more than the brand.
Is there a compressor that does not upload my image?
Yes — Squoosh runs entirely in your browser, so the file never leaves your device. The other tools here, including ours, upload the image but process it in memory without storing it.
Which is best for compressing many images at once?
For no-signup volume, our Image Compressor and iLoveIMG handle a stack without a daily cap. TinyPNG and Optimizilla batch up to about 20 files per round.
Do any of these add a watermark?
None of the six compressors here watermark the output. Watermarking is more common on free PDF and video tools than on image compressors.