Free Image Compressor
Compress JPG, PNG and WEBP images by up to 90% while keeping visual quality. No upload, no registration, instant results.
How to use in 3 steps
No learning curve. No tutorials. Just open and go.
Upload images
Drop one or more images — JPG, PNG, or WEBP. Batch processing available. No file size limit.
Set quality level
Choose compression aggressiveness: light (90%+ quality), balanced (80%), or maximum (60%). Preview the difference before downloading.
Download compressed files
Download individual files or a ZIP archive. Typical size reductions: 40–90% for JPGs, 30–60% for PNGs.
Everything you need to know
Image weight is the single biggest performance bottleneck for most websites. Studies by Google and Akamai show that a 1-second delay in page load reduces conversions by 7%. Images typically account for 50–80% of a webpage's total transfer size.
Modern image compression works by strategically reducing redundant pixel data that the human eye doesn't notice at normal viewing distances and screen sizes. For JPEGs, this means adjusting the quantization tables that control the DCT coefficient precision. For PNGs, it means losslessly re-encoding the PNG data stream.
SiteConversor's compressor uses the browser's native canvas API to re-encode images at your chosen quality level. The key advantage over server-based tools: your images never leave your device. For teams working with confidential product photos, financial documents, or client materials, local processing is a significant privacy benefit.
Practical tip: always compress images before uploading to your website, CMS, or social media. WordPress, Shopify, and most CMSs add their own resizing but often don't apply aggressive enough compression. Pre-compressing your source files gives you control over the quality/size tradeoff.
Frequently Asked Questions
How much can I compress an image without visible quality loss?expand_more
For JPEG photos, 75–85% quality in our compressor typically reduces file size by 60–80% with no perceptible quality difference on screens. For PNG files with lots of solid colors, compression is lossless and size reduction depends on image content.
What is the best compression setting for websites?expand_more
For general website images: 80% quality. For thumbnails and previews: 70% quality. For hero/banner images where quality matters most: 85–90%. After compressing, also consider converting to WEBP format for an additional 25–35% reduction.
Does image compression affect SEO?expand_more
Yes, positively. Google's Core Web Vitals (specifically Largest Contentful Paint and Total Blocking Time) are significantly improved by smaller image files. Google has stated that page speed is a ranking factor. Compressing images is one of the highest-impact SEO optimizations available.
Can I compress PNG files without losing the transparent background?expand_more
Yes. PNG compression in this tool is lossless — it reduces file size by optimizing internal data structure without any quality loss or transparency damage. Typical PNG size reduction: 20–50%.
Can I batch compress 50+ images at once?expand_more
Yes. Select or drag as many images as you want in a single upload. All images are processed locally in your browser — there are no batch limits, no upload caps, and no daily usage restrictions.
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