Image Compressor — Lossless PNG & Batch, No Upload

How To Use

1. Drag one or several images into the box (or click to browse). Because the tool is local-only, even sensitive images never leave your device. You can also press Ctrl + V to paste a screenshot straight in.
2. Pick an output format — PNG, WebP, or JPEG. For PNG, keep Lossless on for pixel-perfect output, or turn it off for a much smaller lossy PNG.
3. Drag the quality slider for lossy output, optionally cap the longest edge (or set a custom size), and watch the saved size update live.
4. Want a specific size? Enter a target in KB and click Compress to target — the tool finds the quality that fits every image.
5. Compare any image with the drag handle, then download each result, copy one straight into a chat or email, or grab the whole batch as a .zip in one click.

Usage Example

A mixed batch of screenshots and photos — 2.4 MB photos at 4032 × 3024 px and 900 KB logos — compressed to WebP at 80% quality with a 2048 px longest edge, typically falls to around 300–500 KB, a reduction of about 80%. Logos and screenshots keep edges razor-sharp with lossless PNG, usually ending up smaller than the original.

Run the same images through again at a lower quality or a tighter resize to see how far they can shrink before quality visibly suffers.

Use Cases

Speed up any website or app by shrinking hero images, product photos, and user uploads before they hit the network. Convert screenshots to lossless PNG and logo designs without touching a pixel. Prepare social media images and email attachments that respect inbox size limits. Archive folders of images in one batch download. Because the compressor is fully local, it is the safe choice for contracts, ID scans, and internal reports you do not want sent to a third-party server — a real privacy difference versus upload-based compressors like TinyPNG.

Best Practices

• Use lossless PNG for screenshots, logos, and anything with text or sharp edges; use WebP or JPEG for photos.
• Start at 80% quality and lower it only until the image still looks acceptable — there is no need to go lower if the file is already small.
• Use the resize option for large photos: capping the longest edge usually saves far more than turning the quality down.
• Compare with the drag handle before downloading, and keep the original until you have confirmed the result looks right.
• Remember your settings are the only thing stored locally — the images themselves are never saved or uploaded.

Frequently Asked Questions

Is my image uploaded anywhere?

No. Everything runs in your browser using canvas, ImageBitmap, and a bundled PNG encoder. Your images never leave your device — safe for screenshots, contracts, and other sensitive files. Nothing is stored after you leave the page.

Does this tool support lossless PNG compression?

Yes. Choose PNG and turn on "Lossless". Results are re-encoded with optimized PNG filtering, so a true lossless PNG (no pixels changed) is produced, usually smaller than the original. This is great for screenshots, logos, and anything with sharp edges or transparency.

Can I compress many images at once?

Yes. Drag in or select several images. They are compressed together with the same settings, shown in a list with per-image savings, and you can download each one or grab every result at once as a .zip. No upload needed.

Can I paste an image or copy the compressed result?

Yes. Press Ctrl / Cmd + V anywhere on the page (or click "Paste image") to drop in an image straight from your clipboard — ideal for screenshots. Each finished result has a "Copy" button that puts the compressed image back on your clipboard, ready to paste into a chat, email, or document. It all stays on your device.

Can I compress to a specific file size?

Yes. Enter a target size in KB and click "Compress to target". The tool searches for the quality that produces a file at or under that size (for example 200 KB) and shows the actual result. This works for lossy outputs — WebP, JPEG, or lossy PNG — because they have a quality knob to tune. It is disabled for lossless PNG: lossless keeps every pixel byte-for-byte identical, so there is no quality to adjust. If you need lossless AND a target size, turn off Lossless for PNG (lossy PNG), switch to WebP / JPEG, or reduce the resize / image dimensions.

Why is "Compress to target" greyed out for lossless PNG?

Because lossless PNG has no quality slider to tune: every pixel is preserved exactly, so there is nothing to lower to hit a smaller size. "Compress to target" works by lowering quality until the size fits, which only makes sense for lossy formats. For an exact target size with lossless, reduce the dimensions (Resize longest edge) or use a lossy format instead.

What if my target size is too small to reach?

Some images cannot be squeezed below a certain size before quality collapses. When the target cannot be reached, the tool shows the smallest size it can achieve and suggests lowering the target, using lossy PNG, or enabling resize.

What is the difference between lossless and lossy PNG?

Lossless PNG keeps every pixel byte-for-byte identical — ideal for text, logos, and screenshots. Lossy PNG (palette quantization) dramatically reduces color count in a way that is hard to notice on photos, producing a much smaller file, much like TinyPNG.

Which output formats are supported?

PNG (lossless or lossy), WebP (lossy), and JPEG (lossy). WebP usually gives great quality at small sizes and supports transparency. JPEG is ideal for photos and maximum compatibility. Animated GIFs are not supported in this version.

What happens to transparency when converting to JPEG?

JPEG has no alpha channel. Transparent areas are filled with white before encoding, so the result stays clean instead of becoming black. Keep PNG or WebP output if you need to preserve transparency.

Can I resize images while compressing?

Yes. Pick a maximum edge length (2048, 1280, or a custom value) per side. Only images whose longest side exceeds that limit are scaled down, which shrinks large photos dramatically.

Does it preserve my photo orientation?

Yes. Images are decoded with EXIF orientation applied, so portrait photos taken on a phone are never rotated or flipped after compression.

Does the tool strip EXIF / GPS metadata?

Yes. Re-encoding in the browser automatically strips EXIF, GPS, and other metadata from the output, so camera and location details never appear in your compressed files — a privacy bonus of fully local processing.

Are my files stored or remembered?

No. Image data is never written to disk or remembered after the page closes. Only your settings (format, lossless toggle, quality, resize, target) are kept, and you can see them in the Privacy panel.

Which input formats are supported?

Common web image formats your browser can decode — including PNG, JPEG, and WebP. Animated GIFs are not supported in this version.

Go Beyond Compression — Visual & Design Tools

Finished shrinking your images? Keep the creative momentum going with these design tools — also 100% local and free:

• CSS Gradient Generator — compose linear & radial gradients and copy the CSS.
• Color Palette & Converter — generate harmony palettes and convert HEX / RGB / HSL.