Lossy compression permanently removes some image data to achieve smaller file sizes. JPEG and WebP use lossy compression by default. At quality 80+, the differences are invisible to the human eye — typical savings are 40–70% compared to an uncompressed source. The key trade-off is that repeated lossy compression compounds quality loss, so always compress from the original file.
Free Online Image Compressor
Shrink Image File Size — Without Sacrificing Quality
Reduce JPG, PNG, and WebP images by up to 80% using smart lossy and lossless compression. Perfect for faster websites and smaller email attachments.
Up to 80% smaller files
Quality presets 50–90%
Lossless PNG crush included
Drop your file here
or browse files
Up to 100 MB free • Outputs: JPG, PNG, WEBP
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SSL Encrypted
Files deleted in 2h
Fast processing
No signup needed
Simple & Fast
How to Use Image Compressor
Convert your files in three simple steps — no software, no signup.
01
Upload Your Image
Drop or browse a JPG, PNG, or WebP image. Files up to 100 MB are supported.
02
Set Compression Level
Choose a quality preset from 50% (maximum compression) to 90% (near-lossless).
03
Download Compressed File
Get your smaller image in seconds. We show you exactly how many bytes you saved.
Features
Why Use Image Compressor?
Faster Page Loads
Smaller images mean lower bandwidth and faster load times — Google rewards this with better SEO rankings.
See Exact Savings
After compression, we show original size, compressed size, and percentage reduction so you know exactly what you gained.
Smart Lossless PNG
PNG files are crushed using OptiPNG-style algorithms to remove metadata and palette bloat without touching pixels.
Private Processing
Files are processed in an isolated session and automatically deleted within 2 hours of upload.
Mobile-Friendly Output
Compressed images load up to 3x faster on mobile networks — critical for user retention on slow connections.
Batch-Ready Workflow
Compress one image now or integrate our API into your workflow to compress thousands automatically.
Compatibility
Supported Formats
All the formats you need, all in one place.
| Format | Description | Extension | Best Used For |
|---|---|---|---|
| JPG (LOSSY) | Quality-based JPEG compression | .jpg |
Photos, blog images, social media |
| JPG (QUALITY 90) | Near-lossless JPEG, minimal artifacts | .jpg |
Portfolio images, product photos |
| JPG (QUALITY 70) | Balanced compression, small size | .jpg |
General web usage, thumbnails |
| JPG (QUALITY 50) | Aggressive compression, visible loss | .jpg |
Previews, low-bandwidth pages |
| PNG (LOSSLESS) | Lossless crush, removes metadata | .png |
Logos, UI assets, transparency |
| WEBP (LOSSY) | WebP with adjustable quality level | .webp |
Modern web images, next-gen CDN |
| WEBP (LOSSLESS) | Lossless WebP for maximum fidelity | .webp |
Icons, diagrams, illustrations |
FAQ
Frequently Asked Questions
For web images, 80% quality is a great balance — typically 40–60% smaller with no visible difference. Use 90% for print-ready files, 50–65% for thumbnails.
No. Compression only reduces file size through encoding efficiency. Width and height remain exactly the same as your original.
PNG compression is always lossless. We remove unnecessary metadata, comments, and redundant palette entries without changing a single pixel.
Typical JPG photos compress 40–70% at quality 80. Images straight from camera apps often contain unused metadata that can be stripped for further gains.
Currently the compressor targets static images. For animated GIF optimization, use our dedicated GIF Maker tool which lets you control frame delay and loop settings.
Free users can compress files up to 100 MB. Most web images are well under 10 MB, making this limit rarely a concern for typical usage.
Real-World Uses
Who Uses Image Compressor?
From everyday users to professionals — see how people rely on this tool every day.
Web Developer
Improve Page Load Speed
Compress hero images, product photos, and blog thumbnails before deployment to reduce LCP and improve Core Web Vitals.
E-commerce Manager
Shrink Product Image Catalogs
Reduce thousands of product photos from 2–5 MB down to under 300 KB without visible quality loss — saving CDN bandwidth costs.
Marketing Manager
Email-Ready Attachments
Most email clients enforce a 10 MB attachment cap. Compress images to ensure your newsletters and pitch decks always get through.
Mobile App Developer
Reduce App Asset Sizes
Compress bundled image assets before including them in your iOS or Android app to shrink download size and improve launch speed.
WordPress Admin
Compress Before CMS Upload
Pre-compress images before uploading to WordPress or Shopify to avoid relying on server-side plugins that slow admin performance.
Photographer
Web-Ready Portfolio Images
Compress high-res DSLR exports (20–50 MB) to shareable web images under 1 MB while keeping them visually stunning.
Why TransmuteBox?
TransmuteBox vs. Alternatives
See how we compare to desktop software and other online converters.
| Feature |
Our Tool TransmuteBox |
Photoshop | Other Online |
|---|---|---|---|
| Lossless PNG crushing | Varies | ||
| Lossy JPEG quality control | Varies | ||
| Shows exact bytes saved | Varies | ||
| No software install | |||
| WebP compression | Varies | ||
| Files auto-deleted (2 h) | Varies | ||
| Free to use | Varies | ||
| API access | Pro |
Under the Hood
Technical Specifications
Built on industry-standard open-source tools for maximum quality and reliability.
Limits & Restrictions
- Max file size: 100 MB (free)
- Supported formats: JPG, PNG, WebP
- Output stays same format as input
MozJPEG
OptiPNG
Pillow
JPEG
PNG
WebP
lossless
Conversion Engine
Pillow 10.x + MozJPEG + OptiPNG
Output Quality
JPEG: quality 50–90 (adjustable); PNG: lossless crush via zlib level 9; WebP: quality 75–90
Average Speed
Typical compression in under 2 seconds for files up to 10 MB
Data Security
HTTPS transfer · isolated temp dir · auto-purged in 2 h
Typical savings
40–80% file size reduction
Visual quality
Indistinguishable at quality 80+
Size report
Before/after bytes shown on result
Complete Guide
Image Compression Explained: Lossy vs Lossless
Image compression is one of the most impactful web performance optimisations available. Understanding the difference between lossy and lossless compression helps you make the right trade-off for every use case.
What Is Lossy Image Compression?
What Is Lossless Image Compression?
Lossless compression reduces file size by encoding data more efficiently without discarding any information. PNG uses lossless compression — every pixel in the output is bit-for-bit identical to the input. Lossless savings are typically 10–30% compared to unoptimised files. It is ideal for logos, screenshots, UI elements, and any image where pixel-perfect accuracy is required.
The Right Quality Setting for Every Use Case
Quality 90 — near-lossless, ideal for portfolio photos and client deliverables. Quality 80 — the sweet spot for most web images; typically 50% smaller than the original. Quality 70 — good for thumbnails and previews. Quality 50–65 — aggressive compression for low-bandwidth situations where small size outweighs visual fidelity.
Why PNG Compression Behaves Differently
PNG uses the DEFLATE algorithm (the same as ZIP). The compression level (zlib 1–9) controls how hard the encoder tries to find redundancies — higher levels take longer but produce smaller files. We always use level 9. We also strip metadata (camera info, timestamps, ICC profiles) unless you specifically need them, saving an additional 5–15 KB on typical files.
The Impact on Core Web Vitals and SEO
Google PageSpeed Insights and Lighthouse flag uncompressed images as a critical performance issue. Images are the single biggest contributor to page weight on most sites. Reducing image payload directly improves LCP (Largest Contentful Paint) — a Core Web Vitals metric that influences your Google search ranking. A 1-second improvement in page load time can increase conversions by 7%.