ImgPrism vs Squoosh: Browser Image Tools Compared
Google's Squoosh is popular for image compression. I compared it with ImgPrism across compression quality, format support, and ease of use.
So people keep recommending Squoosh
Squoosh is made by Google. That alone makes a lot of developers trust it. It shows up in every “best free image compressor” list, usually near the top. I kept seeing it mentioned in forums and on Twitter, so I figured I should test it properly instead of just bookmarking it and moving on.
I’m glad I did. Squoosh is good at what it does, but “what it does” is a pretty narrow lane. I ran the same images through both Squoosh and ImgPrism to see where each one shines and where they fall short.
Both tools process images directly in your browser. Nothing gets uploaded to a server. Your files stay on your machine the entire time. This matters more than people think: Squoosh’s source code is open source on GitHub, so you can actually audit how your files are handled. ImgPrism uses the same browser-local approach, meaning no data leaves your device either way. Both are free, no accounts, no watermarks, no “upgrade to unlock” popups. Both handle JPG, PNG, and WebP.
That is roughly where the similarities end.
Compression test: same photo, different tools
I grabbed a 5.8MB landscape photo from my phone (Pixel 8, 12 megapixels) and ran it through both tools at three quality levels. Here is what came out:
| Quality setting | Squoosh (MozJPEG) | ImgPrism (WebP) | ImgPrism (JPEG) |
|---|---|---|---|
| Quality 90 | 1.42 MB | 1.18 MB | 1.36 MB |
| Quality 80 | 892 KB | 648 KB | 810 KB |
| Quality 60 | 478 KB | 340 KB | 445 KB |
A few things I noticed right away.
Squoosh defaults to MozJPEG as its codec. It does support WebP output, but you have to dig into the dropdown to switch. ImgPrism defaults to WebP and that is where you get the best savings. At quality 80, ImgPrism produced a file 27% smaller than Squoosh’s default output. I zoomed both to 400% and could not find a meaningful difference.
At quality 60, the gap widens. Both images start showing artifacts in sky gradients, but the ImgPrism WebP version holds up slightly better in the shadow areas. Not a huge difference, but it is there if you look for it.
For a pure compression shootout, they are close. Squoosh with WebP selected would probably match ImgPrism almost exactly. The edge goes to ImgPrism mainly because it defaults to the more efficient format.
Which one should you use
If you are a developer who wants exact control over compression parameters and you only need to compress one image at a time, Squoosh is solid. The codec-level tuning is hard to beat, and the side-by-side codec comparison is a feature I genuinely miss when using other tools.
If you are doing practical image work, things like prepping photos for a website, resizing a batch of product images, or adding watermarks, ImgPrism saves you from jumping between three different apps. The batch processing alone makes it worth reaching for first.
Both are worth keeping handy. Squoosh for when I need to nail a specific compression target for a performance-critical hero image. ImgPrism for everything else.
Features and experience
Here is the full feature breakdown.
| Feature | Squoosh | ImgPrism |
|---|---|---|
| Image compression | Yes | Yes |
| Output formats | JPEG, WebP, AVIF, PNG | JPEG, WebP, PNG |
| Resize | No | Yes |
| Crop | No | Yes |
| Format conversion (standalone) | No | Yes |
| Add watermark | No | Yes |
| Rotate / flip | No | Yes |
| Convert to Base64 | No | Yes |
| Batch processing | No (one at a time) | Yes (multiple files) |
| Advanced codec options | Yes (MozJPEG, Oxipng, WebP codec tuning) | No |
| Before/after comparison slider | Yes | Yes |
Squoosh does one thing: compress an image. It gives you fine-grained control over the codec settings, which is great if you know what MozJPEG’s “quantization table” slider does and care about adjusting it.
ImgPrism covers a lot more ground. I resized a batch of 15 product photos last week and compressed them all in one go. Doing that in Squoosh would mean opening each image individually, resizing somewhere else first, then compressing one by one. That is 30 separate operations instead of one.
The watermark feature is something I did not know I needed until I had to stamp a logo onto 20 images for a client deliverable. Saved me from opening Photoshop for a five-minute task.
In terms of feel, Squoosh is unapologetically a developer tool. You drop an image in and it immediately shows you codec parameters, quantization tables, and chroma subsampling options. If you are comfortable with those terms, you will feel right at home. If not, it can feel overwhelming. I know what those settings do and even I found myself just leaving everything at default most of the time.
ImgPrism goes the other direction. You drag your file in, pick a quality level with a simple slider, and hit compress. The advanced options are there if you want them, but they do not stare you in the face on the first screen. It took me about eight seconds from opening the page to downloading my first compressed image.
One thing Squoosh does really well: the before/after drag slider is smooth and satisfying. You can pan around the image while comparing codecs side by side. ImgPrism has a similar comparison view, but Squoosh’s implementation feels a bit more polished for pixel-level inspection. Squoosh also lets you compare two different codec settings at once, split down the middle of the image. That is genuinely useful if you are trying to decide between JPEG and WebP at a specific quality level. I wish ImgPrism had this.
Try the compressor
If you just need to shrink some images quickly, open the image compressor and drag your files in. It handles multiple images at once and you can pick your quality level in about five seconds.