How to Pick a Free Image Compressor — TinyPNG and Beyond

For more than a decade, "image compression" and "TinyPNG" have been almost synonymous in web development circles. The site does one thing well, has a clean UI, and produces results that look identical to the original at a fraction of the file size. There is nothing wrong with TinyPNG — but in 2026 it is no longer the only good option, and "no longer the only" is a useful place to start a comparison.

This article does not crown a winner. It walks through the criteria that actually matter when picking a free compressor and compares three popular options against them: TinyPNG, Squoosh (Google's open-source tool), and toolk's image converter.

The Five Criteria That Actually Matter

When people ask "which compressor is best?" the right answer is "best at what?" Here are five questions worth asking before picking one:

1. Where does the file go? Local processing or server upload?
2. What formats are supported? PNG, JPG, WebP, AVIF, HEIC?
3. What level of control do you have? Smart preset or manual quality?
4. How does it handle bulk? One file at a time, or batches?
5. What is the limit on the free tier? File size, file count per day, dimensions?

A tool can excel on three of these and fail on two. Knowing which two you can live without is half the decision.

Side-by-Side Comparison

TinyPNG — Smart Defaults, Cloud-Based

TinyPNG (and its sibling TinyJPG) uses a custom compression algorithm that dramatically reduces file size with almost no perceptible quality loss. There is no quality slider — you upload, it compresses, you download.

Where it shines. The output quality is consistently excellent across image types. The bulk upload UI is smooth. The API is a long-standing favorite for build pipelines.

Where it falls short.

• Files are uploaded to TinyPNG servers. For website images, that is fine. For private photos or client mockups, it is worth thinking about.
• The free tier is 20 images per month for the web UI; beyond that, you sign up for an API key (still free for ~500/month, then paid).
• 5 MB max per file in the free web UI.
• No format other than PNG, JPG, WebP. No AVIF support.
• No control over the quality level — you take what TinyPNG decides.

Squoosh.app — Maximum Control, Local Processing

Squoosh is an open-source tool from the Google Chrome Labs team. It runs entirely in your browser, with no upload. The killer feature is the side-by-side preview: you can tweak compression settings and instantly see the visual impact next to the original.

Where it shines.

• Local processing, no upload. Fast and private.
• The widest format support of any free compressor — including AVIF, JXL (JPEG XL), MozJPEG, OxiPNG, and WebP v2 in some builds.
• Granular control: per-codec settings, advanced color profiles, resize, rotate, and reduce palette options.
• Open source (MIT). You can self-host or fork it.

Where it falls short.

• No bulk processing. One image at a time. For a folder of 200 product photos, that is brutal.
• The UI rewards expertise and confuses beginners. Choosing between "MozJPEG", "WebP", and "AVIF" is a real question if you do not already know what your target browser support is.
• Development pace has slowed — the project is still maintained but moves quietly.

Toolk Image Converter — Simple, Local, Bulk-Friendly

The toolk image converter is a browser-based tool that focuses on the common case: convert and lightly compress images locally without configuration overhead. It supports PNG, JPG, WebP, HEIC and several other formats, with a basic quality slider and bulk handling.

Where it shines.

• Local processing, no upload, no account, no monthly cap.
• Bulk-friendly — drop a folder of images and convert/compress in one go.
• HEIC support out of the box, useful for iPhone users.
• Simple enough that non-technical users do not need a tutorial.

Where it falls short.

• Less control than Squoosh. A single quality slider, not per-codec advanced settings. No AVIF output as of this writing.
• Less aggressive compression than TinyPNG in some cases — TinyPNG's proprietary algorithm produces marginally smaller files for the same perceived quality on certain images.
• No API for build pipelines.
• Not open source.

Which One to Pick?

The right answer depends on what you are doing:

• You are a developer optimizing a website and want the smallest file size with no fuss? TinyPNG (or its API) is hard to beat. The privacy trade-off is acceptable for public assets.
• You want maximum control, the latest formats (AVIF, JXL), and local processing? Squoosh is the clear pick. Be ready to learn the codec settings.
• You want to convert/compress a folder of personal photos quickly without uploading them? Toolk image converter or Squoosh — toolk is faster for bulk, Squoosh gives you more control per file.
• You handle confidential or private images (medical, ID documents, client work under NDA)? Anything that uploads is out — Squoosh or toolk only.

There is no shame in mixing tools. Many people use TinyPNG for public web assets and a local tool for everything else. The only mistake is treating "the tool I always use" as "the only tool."

A Note on Compression Quality

Compression quality differences between modern free tools are smaller than the marketing suggests. On a typical web photo, TinyPNG, Squoosh (with sensible MozJPEG settings), and toolk produce files within 5-10% of each other in size for indistinguishable visual quality. The decision is rarely about absolute byte savings — it is about workflow, privacy, and control.

Going Further

If local processing is important to you, the image converter on toolk handles PNG, JPG, WebP, HEIC and more in your browser. The tutorials section covers compression, format conversion, and EXIF data removal step by step.