7 Best Free Image Compressor Tools in 2026
I tested dozens of image compressors to find the ones that are actually good — and actually free. Here are seven tools that stood out, each with a different strength.
How I tested
I compressed the same set of five images through each tool: a 5 MB DSLR photo, a 2 MB screenshot, a 1.2 MB product image, a 800 KB illustration, and a 400 KB icon. I compared output file sizes, visual quality, speed, and ease of use. I also checked whether each tool uploads files to a server.
1. MiniPx — best for privacy and target sizes
MiniPx compresses images entirely in your browser. No signup, no upload limits, no server involved. What makes it stand out is the target file size feature — you can compress to exactly 50 KB, 100 KB, or 1 MB, which is perfect for form submissions and email attachments.
It handles JPEG, PNG, WebP, and even HEIC (iPhone photos). Batch compression works well, and the mobile experience is solid. The Smart preset handles most situations without any tweaking.
Best for: People who need specific file sizes, care about privacy, or compress images on mobile devices.
2. TinyPNG — best for PNG optimization
TinyPNG has been around for years and does one thing very well: compress PNG files. Their custom quantization algorithm reduces PNG colors intelligently, producing smaller files than most other tools. They also handle JPEG and WebP now.
The trade-off is privacy — your files are uploaded to their servers. The free tier limits you to 500 compressions per month and 5 MB per file. They also offer a useful WordPress plugin and developer API.
Best for: Developers who need an API or WordPress plugin for automated compression.
3. Squoosh — best for codec experimentation
Built by the Google Chrome team, Squoosh lets you compare different codecs side by side — MozJPEG, WebP, AVIF, OxiPNG, and more. The visual comparison slider shows you exactly what quality you are sacrificing at each compression level.
It processes images in your browser using WebAssembly. The downsides: no batch support (one image at a time), and the interface is tricky on mobile. But for finding the optimal codec and quality settings, nothing beats it.
Best for: Developers and designers who want fine-grained control over compression settings.
4. iLoveIMG — best all-in-one web tool
iLoveIMG is part of a suite that includes iLovePDF and other tools. It offers compression, resizing, cropping, format conversion, and watermarking all in one place. The interface is clean and beginner-friendly.
It uploads files to their servers for processing. The free tier has usage limits and shows ads. But if you want a single tool that does everything image-related, iLoveIMG covers a lot of ground.
Best for: Non-technical users who want one tool for all image tasks.
5. Compressor.io — best visual quality preview
Compressor.io offers both lossy and lossless compression with a nice visual preview. You can toggle between the original and compressed versions to judge quality before downloading. It supports JPEG, PNG, SVG, and GIF.
Like TinyPNG, it is server-based. The free version limits file size to 10 MB and processes one file at a time. The Pro plan adds batch processing and higher limits.
Best for: Designers who want to preview quality differences before committing.
6. XnConvert — best desktop batch processor
XnConvert is a free desktop application for Windows, Mac, and Linux. It handles batch processing of hundreds or thousands of images with a wide range of adjustments — compression, resizing, cropping, watermarking, and format conversion.
It processes everything locally on your machine, so there are no privacy concerns. The interface looks dated but is extremely capable. If you regularly process large batches of images, XnConvert is hard to beat.
Best for: Photographers and e-commerce sellers who process hundreds of images at a time.
7. ImageOptim — best for macOS users
ImageOptim is a free, open-source Mac app that squeezes files using multiple optimization tools under the hood — MozJPEG, pngquant, Zopfli, and others. Just drag images onto the app window and they get compressed in place (or saved as copies).
Everything runs locally. It strips EXIF data by default and integrates well with macOS workflows. The only drawback is that it is Mac-only — Windows users need to look elsewhere.
Best for: Mac users who want a drag-and-drop desktop tool with excellent compression.
Quick comparison
My recommendation
For most people, a browser-based tool is the most convenient option — no installation, works on any device. Between the browser tools, MiniPx offers the best balance of simplicity, privacy, and features. If you need developer-level codec controls, add Squoosh to your toolkit.
If you process large volumes regularly, install XnConvert (or ImageOptim on Mac) for heavy lifting, and use MiniPx for quick one-off tasks.
Frequently asked questions
Compress, convert, and resize images in your browser. Nothing gets uploaded.
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