Why choose a browser-based image compressor over TinyPNG?

TinyPNG is a cloud service: you upload images to its servers and download the compressed copies (it says uploads are kept for a maximum of 48 hours, then deleted). For random web images that's fine. For brand assets, product screenshots, NDA mockups, or screenshots containing UI text — keeping them on your machine is meaningfully safer. Stax does the entire compression in your browser, using the browser's own image encoder, so the image never leaves your device.

Is the compression quality the same?

Not the same method. TinyPNG uses its own compression, which may well produce smaller PNG files. Stax encodes with your browser's built-in encoder: for JPEG and WebP you set a quality or an exact size in KB, and it searches for the best quality that fits. A browser has no quality setting for PNG, so Stax shrinks a PNG by reducing its dimensions or by converting it to JPEG or WebP, and tells you when it cannot get smaller. For photos the difference is usually small; for flat graphics and screenshots, TinyPNG may save noticeably more.

What are the free limits?

TinyPNG's homepage says free users can upload up to 20 images at once, each up to 5 MB; check its site for any other limits or paid plans. Stax has no usage limit because it runs on your device. Its practical limit is your browser's memory, and it handles one image at a time.

Does Stax support batch compression?

No. Stax compresses one image at a time: choose a file, set a size or quality, and download the result. For many images, TinyPNG's multi-file upload (up to 20 at once) or a command-line tool is faster.

What about WebP / AVIF?

Stax can output WebP (lossy, with a quality or exact-size target) as well as JPEG and PNG. AVIF is not offered yet. For now JPG and WebP cover most web image needs.

TinyPNG Alternative

A free TinyPNG alternative: compress PNG, JPG and WebP entirely in your browser, or hit an exact KB target. No upload and no daily limits.

Last updated: 15 October 2026

Feature	TinyPNG	StaxFree
PNG compression	✅	⚠️
JPG compression	✅	✅
AVIF output	✅	❌
Exact target size in KB	Not stated on its homepage	✅
Where images are processed	On its servers (kept up to 48 hours, then deleted)	In your browser
Batch upload	Up to 20 images at once	One image at a time
Free limits	20 images at once, 5 MB each (per its homepage)	No usage limit; browser memory is the ceiling
Developer API	✅	❌

→ Image Compressor

Compress PNG, JPG, WebP — in browser.

Image Resizer →

Resize to social-media presets.

Format Converter →

PNG ↔ JPG ↔ WebP.

Best TinyPNG Alternative in 2026 — Browser-Based Image Compression Comparison

TinyPNG is a well-known image compressor with its own compression for PNG and JPG and a very simple interface. But TinyPNG is a cloud service: images are uploaded to its servers, and its free use is limited to 20 images at a time of up to 5 MB each. A browser-based tool such as Stax Image Compressor runs the compression on your device using the browser's own image encoder, so there is no upload, no usage limit and no waiting for a server. This page is an independent comparison, last checked against TinyPNG's and Squoosh's own pages on 15 October 2026; Stax is not affiliated with either.

TinyPNG vs Stax vs Squoosh — detailed comparison

TinyPNG's strengths are its own smart lossy compression, batch uploads of up to 20 images, AVIF support and a developer API for automating compression in build pipelines. Squoosh (from Google Chrome Labs) says it does all its work locally so images never leave your device, and lets you compare codec settings side by side. Stax Image Compressor focuses on one image at a time, entirely client-side: choose a file, set an exact size such as 100 KB or a quality, and download the result, with no account required and no usage limit. The table below compares TinyPNG and Stax.

When browser-based compression is the right choice

For most daily compression tasks — optimising screenshots for documentation, compressing product images before upload, reducing image sizes for email attachments, or preparing social media graphics — the quality difference between TinyPNG and browser-based compression is often small. The practical advantages of browser-local processing are more compelling: confidential product mockups and brand assets never leave your machine, there is no usage limit stopping you part-way through a job, and compression completes without waiting for a server round-trip. TinyPNG may save more on photo-heavy hero images where every kilobyte matters, and it handles batches; a browser-based tool is the better fit when the file should not be uploaded or you want an exact size in KB.

Who this comparison is for

It is for anyone choosing a default way to compress images: developers weighing tools for a build workflow, designers who hit a free-tier limit, and teams whose images should stay on their own machines. If you compress dozens of images in a build pipeline, TinyPNG's API or a command-line tool fits better; if you compress a few images by hand and want them to stay on your device, a browser-based tool fits better.

Privacy and data handling

Stax Image Compressor runs entirely in your browser using the browser's built-in image encoder, so your image files are never uploaded to any server. That keeps confidential and proprietary visual assets on your device.

Frequently asked questions

Why choose a browser-based image compressor over TinyPNG?: TinyPNG is a cloud service: you upload images to its servers and download the compressed copies (it says uploads are kept for a maximum of 48 hours, then deleted). For random web images that's fine. For brand assets, product screenshots, NDA mockups, or screenshots containing UI text — keeping them on your machine is meaningfully safer. Stax does the entire compression in your browser, using the browser's own image encoder, so the image never leaves your device.
Is the compression quality the same?: Not the same method. TinyPNG uses its own compression, which may well produce smaller PNG files. Stax encodes with your browser's built-in encoder: for JPEG and WebP you set a quality or an exact size in KB, and it searches for the best quality that fits. A browser has no quality setting for PNG, so Stax shrinks a PNG by reducing its dimensions or by converting it to JPEG or WebP, and tells you when it cannot get smaller. For photos the difference is usually small; for flat graphics and screenshots, TinyPNG may save noticeably more.
What are the free limits?: TinyPNG's homepage says free users can upload up to 20 images at once, each up to 5 MB; check its site for any other limits or paid plans. Stax has no usage limit because it runs on your device. Its practical limit is your browser's memory, and it handles one image at a time.
Does Stax support batch compression?: No. Stax compresses one image at a time: choose a file, set a size or quality, and download the result. For many images, TinyPNG's multi-file upload (up to 20 at once) or a command-line tool is faster.
What about WebP / AVIF?: Stax can output WebP (lossy, with a quality or exact-size target) as well as JPEG and PNG. AVIF is not offered yet. For now JPG and WebP cover most web image needs.

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