Best Free Image Compressors: TinyPNG vs Squoosh vs BulkImagePro

I’ve probably compressed a quarter million images over the last few years. That sounds impressive until you realize most of those happened in batches of 200+ at a time — product photos for e-commerce clients, blog image libraries during site migrations, portfolio updates where every single photo needed to drop from 4MB to something a browser wouldn’t choke on.

Along the way, I’ve tried just about every free compressor out there. Some are great. Some are fine. A few made me want to throw my laptop across the room. But three tools keep coming up in every conversation I have with other developers, designers, and content creators: TinyPNG, Squoosh, and BulkImagePro.

So here’s what I actually think about each of them — not a sanitized marketing comparison, but what it’s like to use these tools when you’ve got real work to do.

The Quick Rundown

Before we get into the weeds, here’s how the three stack up on the features that matter most:

Feature	TinyPNG	Squoosh	BulkImagePro
Price	Free (limited) / Paid API	Completely free	Completely free
Batch processing	20 images via web, 500/month via API	No — single image only	Yes — unlimited
Processing location	Their servers	Your browser	Your browser
Input formats	JPEG, PNG, WebP	Most formats	JPEG, PNG, WebP
Output formats	Same as input	Multiple (JPEG, PNG, WebP, AVIF, etc.)	JPEG, PNG, WebP, AVIF
Quality control	Automatic	Visual slider with preview	Adjustable quality setting
Max file size	5MB per image	No limit	No practical limit
Requires account	No (web) / Yes (API)	No	No

That table tells you a lot, but it doesn’t tell you what it’s actually like to use each tool. And that’s where things get interesting.

TinyPNG: The Veteran Everyone Knows

TinyPNG has been around since 2014, and there’s a reason it’s usually the first tool people mention. It just works. You drop your images on the page, it crunches them, and you download the results. The whole interaction takes about 30 seconds.

The compression quality is genuinely excellent. TinyPNG uses smart lossy compression that’s particularly good with PNG files — it reduces the number of colors in the image in a way that’s almost invisible to the eye while dramatically cutting file size. For JPEGs, it strikes a solid balance between size reduction and visual quality. I’ve thrown thousands of product photos through it and rarely been disappointed with the output.

But here’s where it gets annoying.

The free web version caps you at 20 images per upload. If you’re compressing a handful of blog images, that’s plenty. If you’re processing a product catalog? You’re going to be sitting there dragging and dropping batches for a while. Their API raises that to 500 images per month, which is better, but you’ll need to set up API keys, write a script (or use a plugin), and if you’re on the free tier, you’ll hit that 500-image ceiling faster than you’d think.

The other thing that nags at me is the server upload. Every image you compress gets sent to TinyPNG’s servers, processed there, and sent back. For most use cases that’s fine — they have a clear privacy policy and delete images after processing. But if you’re working with confidential mockups, unreleased product photos, or anything under NDA, uploading to a third-party server might not fly with your legal team. I’ve had two clients specifically ask me not to use cloud-based compression tools for exactly this reason.

Where TinyPNG shines: Quick compression of small batches when you just need something that works without fiddling. The WordPress plugin is also solid if you want automated compression on upload.

Where it falls short: Anything involving more than 20 images at once on the web, or situations where you can’t upload images to external servers.

Squoosh: The Tool for Perfectionists

Squoosh is Google’s contribution to the image compression world, and it approaches the problem from a completely different angle. Where TinyPNG says “trust us, we’ll pick the right settings,” Squoosh says “here’s every knob — go wild.”

The interface is genuinely clever. You get a side-by-side slider that lets you compare the original image with the compressed version in real time. Drag the slider back and forth, adjust the quality setting, switch codecs, and watch the file size change instantly. It’s the best way I’ve found to understand exactly what compression is doing to a specific image.

And because Squoosh runs entirely in your browser using WebAssembly, nothing gets uploaded anywhere. Your images stay on your machine. It also supports a wider range of codecs than most tools — you can output to AVIF, WebP, MozJPEG, OxiPNG, and a few others. If you’re curious about how different next-gen image formats perform on your specific images, Squoosh is a fantastic way to experiment. The AVIF vs WebP comparison gets a lot clearer once you’ve played with Squoosh’s codec settings on a few of your own photos.

So what’s the catch? It only handles one image at a time.

That’s it. That’s the whole problem. And it’s a big one.

Squoosh is designed for careful, deliberate compression of individual images. It’s not built for batch work. If you have 50 product photos to compress, you’re opening each one individually, adjusting settings, exporting, and repeating. I’ve done this exactly once — compressing 30 hero images for a redesign — and it took me an entire afternoon. The results were beautiful. But an entire afternoon.

Google did create a Squoosh CLI that handles batches, but it’s been deprecated and is no longer maintained. So the browser tool is really what you’ve got.

Where Squoosh shines: When you need absolute control over a single important image — a hero banner, a featured product shot, a portfolio piece where compression quality really matters.

Where it falls short: Any workflow involving more than a handful of images. There’s no batch capability, and there’s no realistic workaround. If you need batch alternatives, there are other tools worth considering.

BulkImagePro: Built for the Batch Workflow

Full disclosure: this is our tool, so take what I say with that context. But I’ll be straightforward about what it does well and where it has limitations.

BulkImagePro was built specifically because I got tired of the gap between TinyPNG and Squoosh. TinyPNG could batch, but only 20 at a time and only through server uploads. Squoosh gave me great quality and privacy, but wouldn’t do more than one image. I wanted both: batch processing that runs locally in the browser.

That’s what BulkImagePro does. You drag your images in — as many as you need — pick your quality settings and output format, and everything processes right there in your browser. No server upload, no account, no monthly limits. Your images never leave your device.

The output format flexibility is a big part of the workflow. You can take a folder of PNGs, compress them, and output as WebP or AVIF in one pass. For anyone doing format conversion at scale, that’s a real time saver. And if you’re not sure which format to pick, our guide to image compression covers the trade-offs in detail.

Beyond compression, BulkImagePro also handles bulk resizing, cropping, and format conversion — so if you need to resize and compress a batch of images, you can do it in one tool rather than bouncing between three.

Now, what BulkImagePro doesn’t do: it doesn’t give you Squoosh’s side-by-side visual comparison slider. You set a quality level and trust the output. For most batch work that’s exactly what you want — consistency across hundreds of images. But if you’re agonizing over the perfect compression level for a single hero image, Squoosh’s visual preview is hard to beat.

It also doesn’t have TinyPNG’s ecosystem of plugins and integrations. There’s no WordPress plugin that auto-compresses on upload, no Photoshop extension, no Shopify app. BulkImagePro is a web tool. You go to it, you use it, you’re done.

Where BulkImagePro shines: Processing large batches of images quickly with full privacy. If you’ve got 100+ images and you don’t want them leaving your machine, this is the tool.

Where it falls short: No visual preview comparison, no CMS plugin ecosystem, no API for automated workflows.

When Each Tool Actually Makes Sense

Comparisons are nice, but let me get specific about real scenarios.

You’re launching an e-commerce store with 200 product photos. You need consistent compression across every image, you want WebP output for fast loading, and you don’t want to spend all day on it. This is BulkImagePro territory. Drag in the full batch, set quality to 80, output as WebP, done. If you’re working on Shopify specifically, check out our Shopify image optimization guide for the full workflow.

You’re a blogger publishing a post with 4 images. Any of the three tools works fine here. TinyPNG is probably the fastest since you’re under the 20-image limit. But honestly, at this scale the differences are marginal.

You’re a designer compressing a hero image for a client’s homepage. Squoosh. Hands down. That visual preview slider lets you find the exact sweet spot where quality meets file size. Spend the time — it’s one image, and it matters.

You’re migrating a WordPress site with 500 blog images. BulkImagePro in batches, or TinyPNG’s API if you’ve already integrated it into your build pipeline. Either way, you need something that handles volume. If you want the full process mapped out, our guide on batch image compression walks through several approaches.

You’re working with confidential images — unreleased products, client materials under NDA. BulkImagePro or Squoosh. Both process locally. BulkImagePro if you’ve got multiple images, Squoosh if it’s one at a time. TinyPNG requires uploading to their servers, which might be a non-starter.

You want to experiment with AVIF before committing to it. Squoosh for experimentation (the visual comparison is invaluable for a newer format), then BulkImagePro for the actual batch conversion once you’ve settled on your settings. Our AVIF vs WebP comparison can help you decide if the switch is worth it for your use case.

The Privacy Question No One Talks About

Here’s something that doesn’t come up enough in tool comparisons: where do your images go when you compress them?

With TinyPNG, they go to TinyPNG’s servers. The images are uploaded, processed remotely, and the compressed versions are sent back to you. TinyPNG states in their terms that images are deleted after processing, and I have no reason to doubt that. But “uploaded to a third party” is “uploaded to a third party,” regardless of what happens afterward. For personal blog photos, that’s a non-issue. For a client’s unreleased product line? Different conversation.

Squoosh and BulkImagePro both use client-side processing. The images never leave your browser. The compression algorithms run locally via WebAssembly or JavaScript, and the processed files are generated right on your machine. There’s nothing to trust because there’s no server involved.

This isn’t a dealbreaker for most people. But for agencies handling sensitive client work, for companies with strict data handling policies, or for anyone who’s just privacy-conscious on principle — the local processing approach removes a variable you don’t have to think about.

What About Quality? Are They All the Same?

Not exactly, but the differences are smaller than you’d think.

TinyPNG uses proprietary lossy compression and does a particularly good job with PNG files. Their algorithms are mature and well-tuned. On a typical photograph compressed to a similar file size, TinyPNG tends to produce slightly cleaner results than a generic JPEG encoder at the same quality setting.

Squoosh gives you access to MozJPEG (an improved JPEG encoder), WebP, AVIF, and others. Because you control the exact settings, you can often get better results than any automatic tool — if you’re willing to invest the time tweaking. The underlying compression techniques are the same regardless of tool, but Squoosh lets you choose which ones to apply.

BulkImagePro uses browser-native compression with quality settings you control. The results are very good for batch work. You’re trading the per-image perfection of Squoosh for consistency and speed across large sets. For most web use cases — product photos, blog images, thumbnails — the quality difference is imperceptible.

Bottom line: if you’re compressing images for the web (not print, not medical imaging, not fine art reproduction), all three tools will give you results that look great. The quality differences between them are dwarfed by the quality difference between “compressed with any of these tools” and “not compressed at all.”

So Which One Should You Use?

Honestly? Probably more than one.

My actual workflow looks like this: Squoosh for the handful of hero images that really matter, BulkImagePro for everything else. I haven’t used TinyPNG much since switching to BulkImagePro for batch work, but I still recommend it to people who want the simplest possible “drop and download” experience for small batches.

There’s no single best compressor because there’s no single use case. The person compressing 3 blog images has different needs than the person compressing 300 product photos. Picking the right tool for the right job beats trying to find the one tool that does everything.

If batch processing and privacy are your priorities — and for most professionals managing image-heavy sites, they should be — give BulkImagePro a try. It’s free, it runs in your browser, and your images stay on your machine.

For more on the technical side of how compression actually works, our complete guide to image compression covers everything from lossy vs. lossless to format selection to quality benchmarks.

Frequently Asked Questions

Is TinyPNG actually free?

The web version is free for up to 20 images per upload with a 5MB per image limit. Their API offers 500 free compressions per month. Beyond that, you’ll need a paid plan. For occasional use, the free tier is plenty. For regular batch work, you’ll hit the limits quickly.

Does Squoosh work offline?

Yes — once you’ve loaded Squoosh in your browser, it installs as a Progressive Web App (PWA) and works offline. All processing happens locally, so you don’t need an internet connection after the initial load. It’s one of the tool’s underrated features.

Which compressor produces the smallest files?

It depends on the image content and format. For PNGs, TinyPNG often edges out the others because its palette reduction is particularly well-tuned. For photographs in AVIF format, Squoosh gives you the most control to squeeze out every byte. For batch work at consistent quality, all three produce comparable results. The format matters far more than the tool — converting a JPEG to WebP or AVIF will typically save more than switching between compressors using the same format.

Can I use BulkImagePro for GIF compression?

BulkImagePro is built for static image formats — JPEG, PNG, and WebP. For GIF-specific tools, you might want to look at EzGIF alternatives that handle animated formats. If your GIFs are actually short clips, converting them to video (MP4 or WebM) will usually give you much better file sizes than any GIF compressor.

Is it safe to upload images to TinyPNG?

TinyPNG uses HTTPS for transfers and states that images are deleted from their servers after compression. For general web images, it’s perfectly safe. For sensitive or confidential images — unreleased products, client work under NDA, private documents — you might prefer a client-side tool like BulkImagePro or Squoosh that doesn’t upload anything.

What quality setting should I use for web images?

For JPEG and WebP, a quality setting of 75-85 covers most web use cases well. Below 75, you’ll start noticing artifacts in detailed areas. Above 85, file sizes increase faster than visual quality improves. The sweet spot varies by image — photographs with lots of smooth gradients can tolerate lower quality than images with sharp text or fine details. Start at 80 and adjust from there.