Image Compressor: Reduce JPG, PNG, WebP File Size Online
Reduce JPG, PNG, and WebP file size online with adjustable quality, side-by-side comparison, and batch mode: no upload needed.
Updated 2026-08-16
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Features
- Compress JPG, PNG, and WebP images with adjustable quality slider
- Interactive before/after comparison slider: drag to reveal differences
- Batch compression: open and compress multiple images at once
- Quality presets for quick optimization: Smallest, Web, Balanced, High
- Real-time file size comparison bar showing exact savings
- Save individual images or batch save as ZIP
- Paste from clipboard (Ctrl+V) for instant compression
- No file size limits on input images
How to Use
- 1Open images by clicking the drop area, dragging files, or pasting from clipboard (Ctrl+V).
- 2Choose an output format (JPEG, PNG, or WebP) from the sidebar.
- 3Use quality presets for quick optimization, or fine-tune with the slider.
- 4Drag the before/after comparison slider to inspect compression differences at full resolution.
- 5Review file size savings shown in the real-time comparison bar.
- 6Click Save to save individual images, or Save All to save as ZIP.
- 7How to compress an image for email attachment: open the image, set quality to 60–70% for maximum compression, select JPEG format for photos. The real-time size bar shows if the result fits your email's attachment limit before saving.
- 8How to find the best quality-size balance: open your image, start at 80% quality and use the before/after slider to compare. Gradually lower quality in 5% steps until you find the point where file size is acceptable but quality still looks good to your eyes.
- 9How to batch compress images for a website gallery: open all your gallery images at once, set quality to 80% for WebP output, verify a few images with the comparison slider, then click Save All to get the entire optimized gallery as a ZIP file.
Frequently Asked Questions
How much can I compress an image?
The amount of compression depends on the image content and format. For JPEG and WebP, lower quality settings produce smaller files. A quality setting of 60–80% typically reduces file size by 40–80% with minimal visual loss. PNG compression is limited since PNG is already a lossless format.
Why does WebP compress better than JPEG?
WebP generally provides 25–35% better compression than JPEG at the same visual quality level. For web use, WebP is recommended. JPEG is more universally supported. PNG is best when you need lossless quality, but file sizes will be larger.
Why doesn't image compression reduce the image dimensions?
Because compression adjusts the file size, not the pixel dimensions; this tool only changes the compression quality, so the output image keeps the exact width and height of the original. A smaller file with the same dimensions is normal. To change dimensions, use the Image Resizer tool.
What quality setting should I use for web images?
For JPEG and WebP, 80–90% is recommended for high-quality images where file size still matters. For maximum compression, 50–60% can work well for photos with less detail. Use the before/after slider to compare and find the sweet spot for your specific images.
Can I compress images in batches?
Yes. Open multiple images at once; they all appear in the list. You can compress them with the same quality setting and output format. Save them individually or click Save All to get a ZIP archive of all compressed images.
Does compression support transparency?
PNG and WebP formats support transparency. Compressing a PNG with transparency preserves the alpha channel. JPEG does not support transparency; transparent areas will be filled with white when converting to JPEG output.
Is there a limit on file size?
Since all processing happens in your browser, the practical limit depends on your device's available memory. Most images under 50MB work fine. Very large images (100MB+) may cause performance issues on lower-end devices.
Can I compress an image to a specific file size, like 100KB or 500KB?
There is no target-size mode; you control the quality manually. Start at 80% and read the live size bar, then lower in 10% steps until you hit the target. Photos reach small sizes easily; PNG screenshots and flat-color graphics compress much less. If the target is hard to reach, switch the output format to WebP or JPEG and retry.
Why can't I compress my image below a certain size?
Content sets the floor: photos with noise or gradients keep little redundancy, camera JPEGs are already compressed, and PNG with transparency cannot drop the alpha channel. Below a point, the size barely shrinks while quality visibly suffers. In that case keep the original or reduce the dimensions with the Image Resizer tool instead.
What's the best output format for web images?
WebP is generally the best choice for web images because it offers superior compression with transparency support. JPEG is good for photos without transparency needs. PNG is best when you need lossless quality, such as for screenshots with text or UI elements.
Can I compress SVG files?
No. This tool works with raster image formats (JPEG, PNG, WebP) that use pixel-based compression. SVG is a vector format with a different compression approach. For SVG optimization, look for a dedicated SVG minifier tool.
Why is my compressed image bigger than the original?
This happens mainly with PNG: PNG is already lossless, so re-encoding it cannot shrink it, and the re-encoding can occasionally add a few bytes. It also happens with already-optimized files (camera output, images previously compressed) that have no redundant data left, and with small or flat-color images where the format overhead dominates. If the preview shows no size reduction, keep the original; compressing further would only degrade quality.
Why can't this free image compressor online get my photo under 20KB?
20KB is very small for a photo: a 4000x3000 image needs heavy quality loss to fit. Start at 50-60% quality, watch the live size bar, and lower it step by step; if it still does not fit, reduce the dimensions first with the Image Resizer tool (halving both sides cuts the file size by roughly 4x), then compress again. Flat-color graphics and screenshots can reach 20KB, but detailed photos often cannot without visible damage.
Why does compressing a text screenshot make it blurry and unreadable?
JPEG and WebP at low quality discard high-frequency detail (exactly where text edges live), so small text becomes unreadable. Screenshots with text should stay lossless: PNG (large but crisp) or WebP at 85-90% quality, which usually keeps text readable at a fraction of PNG's size. Set this image compressor to WebP output for text-heavy screenshots, and flat-color UI shots compress extremely well too.