Compress JPG, PNG and WebP Images Online
Re-encode JPEG and WebP images with an adjustable quality setting, or optimize PNG files losslessly. The original format is preserved.
How Image Compression Works
Digital images contain far more data than most screens can display. A photo taken on a modern smartphone at 12 megapixels generates a raw file of 36MB — but the same photo saved as a JPEG at 85% quality is typically 3–5MB with no perceptible quality difference on a screen.
Our tool uses Pillow, Python's most widely-used image processing library, to re-encode images at your chosen quality level. For JPEGs, this reduces the amount of image data stored while applying smart algorithms to preserve the most visually important details. For PNGs, we apply lossless optimization to reduce file overhead without any quality change.
Quality Setting Guide
| Quality % | Use Case | Typical Reduction |
|---|---|---|
| 85–95% | Professional photography, print, archival | 40–60% |
| 70–85% | Web display, social media, email | 60–75% |
| 50–70% | Thumbnails, previews, quick sharing | 75–85% |
| 10–50% | Minimum file size, low quality acceptable | 85–95% |
For most web use cases — blog images, social media posts, email attachments — quality 75 is the sweet spot. The file is typically 60–70% smaller than the original with no visible difference on screen.
JPG vs PNG vs WebP — Which Compresses Better?
JPG: Best for photographs and complex images with gradients. Lossy compression means quality degrades with each save, but the files are very small. A 5MB JPG typically compresses to 1–2MB at quality 75.
PNG: Best for images with text, sharp lines, transparency, or flat colors. Lossless — compression reduces file overhead without quality loss. A 2MB PNG might compress to 1.4MB. For photos, PNG files are larger than equivalent JPGs.
WebP: Modern format that achieves 25–35% smaller files than JPG at equivalent quality. Excellent for web use. Not all applications support WebP — if compatibility matters, stick with JPG or PNG.
Need to change format? Use our Image Convert tool to convert between JPG, PNG, WebP, BMP, and GIF.
Related Guide
Need practical quality settings? Read our guide on how to compress images without losing quality, including JPG, PNG and WebP examples.
Frequently Asked Questions
Will compressed images look blurry?
At quality 75 and above, compression artifacts are typically invisible on screen. You'd need to zoom to 200%+ to see any difference. Below quality 50, artifacts become visible — most noticeable in areas with fine texture or sharp edges.
Can I compress multiple images at once?
Currently the free tool processes one image at a time. Batch compression is available for users who need to process many images.
Does compression work on transparent PNGs?
Yes. Transparency is preserved in PNG output. Converting a transparent PNG to JPG removes transparency (JPG doesn't support it) — stick with PNG if you need transparent backgrounds.
What's the best quality for website images?
75–80% quality for photography, 85–90% for product images where detail matters. Google's PageSpeed Insights and WebP format both recommend 75–85% as the optimal balance for web performance.
Compression vs. Quality: Finding the Right Balance
Image compression always involves a trade-off between file size and visual quality. The goal is to find the point where the file is as small as possible while the quality is still acceptable for the intended use. "Acceptable" varies by use case — a print-ready product photo needs higher quality than a blog thumbnail.
At quality 75-85%, most people cannot tell the difference between a compressed image and the original when viewing on a screen at normal size. The compression artifacts only become visible at high zoom levels (150%+) in areas with fine texture or smooth gradients. For web use, quality 75 is the standard recommendation and the default we use.
The Math Behind File Size Reduction
JPEG compression works by dividing the image into 8×8 pixel blocks, applying a frequency transform to each block, and quantizing the resulting coefficients. Lower quality settings apply more aggressive quantization, discarding the high-frequency details that encode fine texture. The eye is more sensitive to brightness variations than color variations, so color channels are compressed more aggressively than the brightness channel.
A 6MB original photo at quality 75 becomes approximately 1.2MB — an 80% reduction. The 4.8MB difference is mostly high-frequency texture data that's imperceptible to the human eye at normal viewing distance.
Why Image File Size Matters for Websites
Page load speed directly affects search engine rankings, bounce rates, and conversion rates. Google's Core Web Vitals include Largest Contentful Paint (LCP) — how long it takes for the main image on a page to load. A hero image that's 3MB takes 6+ seconds to load on a typical mobile connection. The same image compressed to 400KB loads in under 1 second.
Google's PageSpeed Insights consistently lists "Serve images in next-gen formats" and "Efficiently encode images" as top optimization opportunities for most websites. Both mean the same thing: compress and convert your images before uploading them.
WebP vs JPG — The Practical Difference in 2026
WebP is now supported by all major browsers (Chrome, Firefox, Safari, Edge) and produces files 25-35% smaller than JPG at equivalent quality. For a website serving thousands of images, this translates to significant bandwidth savings and faster load times. Our tool compresses JPG and PNG, and for format conversion to WebP, use our image convert tool.
| Quality Setting | Typical Reduction | Use Case | Visible Difference? |
|---|---|---|---|
| 90-95% | 40-60% | Print, archival, professional | None |
| 75-85% | 60-80% | Web, social media, email | None at normal view |
| 60-75% | 75-88% | Thumbnails, previews | Slight, in smooth areas |
| 40-60% | 85-93% | Maximum compression | Visible artifacts |
Compress Before Uploading — Why It Matters
Most content management systems, e-commerce platforms, and social media sites recompress images on upload. WordPress compresses to 82% quality by default. Instagram recompresses all uploads. Uploading a pre-compressed image at your desired quality level gives you control over the final output rather than leaving it to the platform's algorithm — which may compress more aggressively than you'd like.
Related Tools
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Reduce pixel dimensions too, for an even smaller file.
Convert Image
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Remove the background before compressing product or portrait photos.
Compress PDF
Shrink a PDF the same way, if that's what you're actually working with.