100% browser-based · zero upload

Compress images up to 80% smaller without losing what matters.

Compressly is a free online image compressor and converter for JPG, PNG, WebP, AVIF and JXL. Batch-compress and convert between every modern image format with the same open-source codecs as Google's Squoosh — all running in your browser, nothing uploaded.

No signup. No file uploads. No watermark. Start compressing — it's free.

What Compressly does

• Zero upload, zero risk. Compression happens locally in your browser using WebAssembly. Your files never leave your device — verify it in the Network tab.
• Real batch, not one-at-a-time. Drag a folder of 200 images and walk away. Work is spread across up to four Web Workers in parallel.
• Every modern format. JPG, PNG, WebP, AVIF and JXL — decode and encode in any direction.
• Quality you can dial. Quality slider, lossless mode, encoder effort and resize controls.
• Built on proven codecs. MozJPEG (Mozilla), OxiPNG, libwebp (Google), libavif (AOMedia) and libjxl, compiled to WebAssembly.

Converters

• Convert PNG to WebP — keep transparency, cut file size 25–80%.
• Convert JPG to WebP — same photo quality, typically 25–35% lighter.
• Convert WebP to PNG — a universal, lossless, editable file.
• Convert WebP to JPG — maximum compatibility for email and uploads.
• Compress WebP PNG to AVIF JPG to AVIF AVIF to JPG AVIF to PNG AVIF converter — make existing WebP files smaller without changing format.

Pricing

Free — up to 20 images per batch, 25 MB per file, JPG/PNG/WebP/AVIF, quality slider, resize and ZIP download. Pro — $39 one-time (lifetime, no subscription) — unlimited batch size, 200 MB per file, JXL encoding and decoding, lossless mode and EXIF preservation.

Frequently asked

How does Compressly compress images?

Compressly uses the open-source MozJPEG (Mozilla), OxiPNG, libwebp (Google), libavif (AOMedia) and libjxl encoders compiled to WebAssembly — the same codec family as Google's Squoosh. All compression runs locally inside your browser; your files never touch a server.

Which image formats are supported?

JPG, PNG, WebP, AVIF and JXL — for both decoding and encoding. You can convert freely between any of them in a single pass.

Is Compressly really free?

Yes, and lossless mode is free too. The free tier handles up to 20 images per batch at 25 MB each across JPG, PNG, WebP and AVIF. Pro ($39 one-time, lifetime) removes the batch limit, raises the size cap to 200 MB, and adds JXL encoding and EXIF preservation.

Are my images uploaded anywhere?

No. Compressly is a static client-side app — there is no server upload step. Open DevTools → Network tab while compressing to verify nothing is sent.

How does Compressly differ from TinyPNG or Squoosh?

TinyPNG compresses on its servers, so your files are uploaded. Squoosh runs locally but works one image at a time. Compressly stays local like Squoosh and adds true batch processing, ZIP export and a one-time Pro license for power users.

What is JXL and why does Pro require it?

JPEG XL (JXL) is a next-generation image format designed for high-fidelity compression and lossless recompression of existing JPEGs. Its encoder bundle is large (~3 MB of WASM), so we gate it behind Pro to keep the free experience fast. Lossless mode itself is free — it works with PNG, WebP and AVIF.

Does Pro work across browsers and devices?

Yes. Your license unlocks Compressly on every browser and device you use it on — no seat limit. Just paste the key into "Have a key?" at the top.

What's your refund policy?

Lemon Squeezy handles billing with a 14-day money-back guarantee, no questions asked. Just reply to your purchase receipt.

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