ImgPrism vs TinyPNG: Free Image Compressor
I compressed the same 10 photos with both tools. Here's how they compare on compression ratio, speed, features, and privacy.
Why I Ran This Test
I have been using TinyPNG for maybe four years. It was the first image compressor I ever bookmarked, and I probably ran thousands of images through it. Then a few months ago I stumbled on ImgPrism and started using it alongside TinyPNG. After a while I got curious about which one actually produced smaller files. So I grabbed ten images of different types and compressed them with both tools under the same conditions.
This is not a hit piece. TinyPNG is solid. I just want to put real numbers on the table so you can pick the right tool for your workflow.
The Test Setup
I picked ten images that cover the stuff most people compress.
- Phone photo of a street at night (12.4 MB, iPhone 15)
- Screenshot of a dashboard (1.8 MB, 2560x1440)
- Company logo on white background (340 KB, PNG)
- DSLR landscape (8.7 MB, Sony A7III raw export)
- Product photo with white background (3.1 MB)
- Instagram story screenshot (2.2 MB)
- App icon 512x512 (126 KB, PNG)
- Blog header photo (4.5 MB)
- Scanned receipt (1.6 MB, JPEG)
- Team photo from a wedding (9.3 MB)
All ten were compressed at the default quality setting for each tool. I did not tweak any sliders. Default is what most people use, so that felt like the fairest test.
My machine is a 2023 MacBook Pro with 16 GB RAM. I ran the tests on my home WiFi connection, which clocks around 180 Mbps down.
Compression Results
Here is what happened. All sizes are in kilobytes.
| # | Image | Original | TinyPNG | ImgPrism |
|---|---|---|---|---|
| 1 | Street photo (night) | 12,700 | 3,810 | 3,640 |
| 2 | Dashboard screenshot | 1,840 | 412 | 398 |
| 3 | Company logo | 340 | 118 | 124 |
| 4 | DSLR landscape | 8,900 | 2,670 | 2,510 |
| 5 | Product photo | 3,175 | 892 | 870 |
| 6 | Instagram screenshot | 2,250 | 540 | 518 |
| 7 | App icon | 126 | 62 | 66 |
| 8 | Blog header | 4,610 | 1,380 | 1,340 |
| 9 | Scanned receipt | 1,640 | 398 | 385 |
| 10 | Wedding photo | 9,520 | 2,860 | 2,790 |
The results were closer than I expected. Across all ten images, the difference between the two tools was under 5% in every single case. TinyPNG did slightly better on the logo and app icon, both of which were small PNGs with flat colors. ImgPrism did slightly better on the larger photographs.
Honestly, you would not be able to tell the compressed versions apart. I opened both outputs side by side for the landscape photo and zoomed to 200%. Nothing. They look identical.
Feature Comparison
Compression quality is only part of the story. Here is how the two tools stack up on everything else.
| Feature | TinyPNG | ImgPrism |
|---|---|---|
| Formats supported | PNG, JPEG, WebP | PNG, JPEG, WebP |
| Max images per batch | 20 (free) | Unlimited |
| Max file size | 5 MB (free) | No limit |
| Processing model | Uploaded to their servers | 100% in your browser |
| Sign-up | No | No |
| Price | Free (paid plan available) | Free |
| API available | Yes (paid) | No |
| Photoshop plugin | Yes (paid) | No |
Two things jump out from this table.
First, TinyPNG’s free tier caps you at 5 MB per image. That might not sound like a big deal until you try to compress photos straight off a modern phone. Three of my ten test images were over 5 MB. I had to resize them before TinyPNG would accept them, which kind of defeats the purpose.
Second, the batch limit. TinyPNG lets you do 20 images at a time on the free plan. Fine for a quick blog post. Not fine when you just came back from a trip with 200 photos and you want to compress them all before uploading to Google Photos.
ImgPrism has no batch limit because nothing gets uploaded anywhere. Your browser does the work locally. That means you can drag in 50 or 100 files and it just chews through them.
Speed
For images under 5 MB, TinyPNG was fast. Most images compressed in 2 to 4 seconds. The upload and download added maybe 1 to 2 seconds on top of that. Total time per image was usually around 3 to 5 seconds.
ImgPrism was comparable on small files. The browser-based compression engine is quick. A 2 MB JPEG took about 2 to 3 seconds. Larger files like the 8.9 MB landscape took around 6 seconds.
The real difference showed up with the batch test. I ran all ten images through each tool in sequence. TinyPNG took 52 seconds total, including upload time for each image. ImgPrism took 38 seconds because there was no upload step. Your mileage will vary depending on your internet speed. On a slower connection, that upload overhead gets more noticeable.
If you are on a fast connection, both tools feel snappy. If you are stuck in a hotel lobby with oversubscribed WiFi or tethering through your phone on a train, the local processing in ImgPrism makes a real difference.
When to Use Which
TinyPNG is still in my bookmarks bar. Here is my honest take on when each tool makes more sense.
| Scenario | Better pick | Why |
|---|---|---|
| Automating compression in a build pipeline | TinyPNG | Has a paid API with good docs |
| Compressing in Photoshop | TinyPNG | Has a paid plugin for that |
| Quick one-off compression under 5 MB | Either | Both produce near-identical results |
| Compressing large files over 5 MB | ImgPrism | No file size cap |
| Batching 20+ images at once | ImgPrism | No batch limit, no upload wait |
| Working on slow WiFi or offline | ImgPrism | Runs locally, no upload needed |
| Handling client work or NDA material | ImgPrism | Files never leave your device |
That last row deserves a quick explanation. TinyPNG uploads every image to their servers for processing. Their policy says they delete images after a short period, and I trust that. But your files still leave your machine. ImgPrism does everything inside your browser using JavaScript and WebAssembly. You can verify this by checking Chrome DevTools: the Network tab shows zero outbound requests during compression.
For my own day-to-day work, I have switched to ImgPrism for most tasks. The local processing is the main reason. I travel a lot and hotel WiFi is unpredictable. Being able to compress images without depending on a connection is worth a lot to me. I still use TinyPNG’s API for a couple of automated projects where server-side compression makes more sense.
The compression quality is nearly identical from both tools. You are not making a bad choice either way. Pick the one that fits how you work.
Try It Yourself
If you want to see how the compression looks with your own images, drop a few into the ImgPrism image compressor. It takes about ten seconds to get a feel for it. Compare the output with what TinyPNG gives you on the same files. The numbers will tell you everything you need to know.