How do I compress an image without losing quality?

Completely lossless compression is only possible with formats like PNG. For significant size reductions, some quality loss is inevitable. However, CompressImg minimizes visible quality loss by using smart quality iteration — it starts with high quality and only reduces as much as needed to hit your target size. For best results, start with a high-resolution original image and choose the largest target size that meets your requirements.

What is the best free image compressor online?

CompressImg is a free tool that requires no registration. It compresses JPEG, PNG, WebP, and AVIF images entirely in your browser — no files are ever sent to a server — and offers customizable maximum sizes (20 KB, 50 KB, 100 KB, 200 KB, or any custom value).

How to reduce image file size for email?

Most email services have attachment size limits. Use CompressImg to compress images before attaching them. For photos, 100 KB per image is usually a good balance of quality and size. For thumbnails or small inline images, 50 KB or even 20 KB works well.

What is the difference between lossy and lossless compression?

Lossy compression reduces file size by permanently removing some image data. JPEG uses lossy compression, which is why it can achieve such small file sizes. Lossless compression reduces file size without losing any data — PNG and GIF use lossless compression. AVIF supports both modes and typically achieves better compression than JPEG at the same quality.

How to compress PNG images online?

Upload your PNG file to CompressImg. The tool processes it using the HTML5 Canvas API and outputs a compressed JPEG (for maximum size reduction) or preserves the source format when the size target allows. No server upload required — everything runs in your browser.

How do I compress an image without losing quality?

Completely lossless compression is only possible with formats like PNG. For significant size reductions, some quality loss is inevitable. CompressImg minimizes visible quality loss by iterating quality levels, starting high and reducing only as needed to hit your target size. For best results, start with a high-resolution original and choose the largest target size that meets your requirements.

What is the best free image compressor online?

CompressImg is a free tool that requires no registration. It compresses JPEG, PNG, WebP, and AVIF images entirely in your browser — no files are ever sent to a server — and offers customizable maximum sizes (20 KB, 50 KB, 100 KB, 200 KB, or any custom value).

How to reduce image file size for email?

Most email services have attachment limits. Use CompressImg to compress images before attaching them. For photos, 100 KB per image balances quality and size; for thumbnails, 50 KB or 20 KB may be sufficient.

What is the difference between lossy and lossless compression?

Lossy compression reduces file size by permanently removing some image data. JPEG uses lossy compression. Lossless compression reduces file size without losing any data — PNG and GIF use lossless compression. AVIF supports both modes and typically achieves better compression than JPEG at the same quality.

How to compress PNG images online?

Upload your PNG file to CompressImg. The tool processes it using the HTML5 Canvas API and outputs a compressed JPEG (for maximum size reduction) or preserves the source format when the size target allows. No server upload required.

Compress Image Online - Free & Fast

Reduce your image file size instantly. Supports JPEG, PNG, WebP, and AVIF formats. All compression runs directly in your browser — your images never leave your device. No account, no watermark, no file size limits.

Target Size:

Drag & drop your image here

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JPG, PNG, WebP supported • Compressed securely

How It Works

1. Upload Image

Drag & drop or click to select your JPG, PNG, or WebP file.

2. Choose Target Size

Select 20KB, 50KB, 100KB, 200KB or enter a custom size.

3. Compress

Our tool automatically finds the best quality for your target size.

4. Download

Get your compressed image instantly. No waiting, no watermarks.

Why Choose CompressImg?

Private & Secure

Our Worker keeps no image copy. TinyPNG may temporarily retain submitted content for up to 48 hours under its terms.

Lightning Fast

Compress images in seconds with our optimized Canvas-based processing engine.

Completely Free

No hidden fees or subscriptions. TinyPNG optimization has a fair-use quota, with local compression as a fallback.

Compress Image to Specific Size

Choose your target file size and start compressing instantly. Perfect for forms, websites, and email attachments.

20KB Compress to 20KB 30KB Compress to 30KB 50KB Compress to 50KB 100KB Compress to 100KB 200KB Compress to 200KB

Free Online Image Compression Tool

In today's digital world, image file size matters more than ever. Whether you're building a website, submitting an online form, or sending images via email, large file sizes can cause problems. Slow loading websites frustrate visitors, email attachments bounce back, and storage space runs out quickly. That's where CompressImg comes in - a free online image compression tool that helps you reduce image file sizes without sacrificing noticeable quality.

Our online image compressor supports the most popular formats including JPEG/JPG, PNG, WebP, and AVIF. The tool is designed with simplicity in mind — no technical knowledge required. Simply upload your image, choose your desired target size (20 KB, 30 KB, 50 KB, 100 KB, 200 KB, or any custom size), and let our tool do the rest. The compression algorithm automatically adjusts quality settings to achieve your target file size while maintaining the best possible visual quality.

All compression runs locally in your browser using the HTML5 Canvas API. No image data is ever transmitted to a server, ensuring complete privacy. No registration, no watermarks, no subscription required.

How Does Image Compression Work?

Image compression works by reducing the amount of data required to represent an image. There are two main types: lossy compression and lossless compression. Lossy compression, which is what most online tools use, reduces file size by permanently eliminating certain information, especially data that the human eye is less likely to notice. JPEG is the most common lossy format. Lossless compression, used by formats like PNG, reduces file size without losing any quality, though the size reduction is typically smaller.

CompressImg uses a two-stage pipeline: images are first sent to TinyPNG through our HTTPS Worker for perceptual optimization. If that result is still above your selected limit, the browser iteratively adjusts JPEG quality and pixel dimensions until the result is at or below the target.

Use Cases for Image Compression

There are countless scenarios where you might need to compress an image to a specific file size. Government websites and job portals often require passport photos or documents under 20KB or 50KB. E-commerce platforms may have listing image size limits. Social media platforms and messaging apps often compress images anyway, so pre-compressing gives you control over the quality. Web developers use image compression to improve page load speeds and SEO rankings. Email services typically have attachment limits, making image compression essential for sharing photos.

With CompressImg, you can handle all these use cases and more. The ability to set custom target sizes means you're not limited to preset options. Whether you need a tiny 20KB thumbnail or a 200KB product image, our tool adapts to your needs on any modern device with an internet connection.