Compress Images for Email Attachments
Most email providers limit attachments to 10–25MB. Large image attachments also take longer to send and receive, and may be blocked by corporate mail servers. Compress your images before attaching them to keep emails fast and deliverable.
Tips
Gmail limit: 25MB total
Gmail supports attachments up to 25MB total per email. For larger files, Gmail automatically converts them to Google Drive links.
Outlook limit: 10–20MB
Microsoft Outlook and Exchange servers typically limit attachments to 10–20MB. Corporate IT policies may set even stricter limits.
Compress to under 1MB per image
For email, compress images to under 1MB each. At this size, even a 10-image attachment stays well within most providers' limits.
Use ZIP for multiple images
Sending many images? Compress them individually then zip the folder. ZIP compression adds another 5–15% size reduction on top of image compression.
Image Compressor
AI & ProductivityCompress JPEG, PNG, and WebP images online without losing quality.
About this tool
What is the Image Compressor?
The Image Compressor reduces the file size of JPEG, PNG, and WebP images without requiring any software installation. Upload an image, adjust the quality level, and download a smaller version — the entire process happens in your browser. Single-image compression is completely free. Batch processing for multiple images at once is available with credits.
Image compression is one of the highest-impact optimizations for web performance. Images are typically the largest assets on a web page, and oversized images are a leading cause of slow load times, poor Core Web Vitals scores, and high bandwidth costs.
How to Use the Image Compressor
- Upload your images. Drag and drop one or more files onto the upload area, or click to browse. JPEG, PNG, and WebP files are supported.
- Adjust the quality level. The quality slider controls the trade-off between file size and visual fidelity. Higher quality preserves more detail; lower quality produces smaller files.
- Choose an output format. Keep the original format, or convert to JPEG, PNG, or WebP. JPEG produces the smallest files for photographs; PNG preserves transparency; WebP offers the best compression for modern browsers.
- Compare before and after. The tool shows the original and compressed images side by side with file sizes for both, so you can judge the quality difference before downloading.
- Download your results. Click Download on any individual file, or use Download All as ZIP when multiple images are ready.
Single Image vs Batch Processing
The first image you upload is always processed for free — no account required. If you upload more than one image, the additional files are queued and processed as a batch using credits. One credit is deducted per additional file. Credits never expire, and your balance is visible in the batch panel before you confirm.
If you do not yet have credits, the batch panel includes a link to the pricing page where you can top up your account.
Lossy vs Lossless Compression
Lossy compression (used for JPEG and WebP) permanently removes image data to achieve smaller file sizes. The removed data is typically imperceptible at moderate quality settings — a JPEG at quality 80 is often visually indistinguishable from quality 100 at a fraction of the size. Once compressed with lossy settings, the removed data cannot be recovered.
Lossless compression (used for PNG) reorganizes the image data more efficiently without discarding anything. The result looks identical to the original, but the size reduction is more modest than lossy compression.
As a general guideline: use lossy compression for photographs and complex images, and lossless for graphics, logos, and images with flat areas of color or transparency.
Why Image Size Matters
Page speed — Google's Core Web Vitals include Largest Contentful Paint (LCP), which measures how quickly the main image on a page loads. Oversized images are the most common cause of poor LCP scores.
SEO — page speed is a ranking factor. Sites that load faster tend to rank higher, and image optimization is the single most impactful step for most sites.
Bandwidth costs — if you pay for CDN bandwidth or have users on mobile connections, smaller images reduce costs and improve the experience for people on slower networks.
Storage — compressed images take up less disk space, which matters for sites with large image libraries or limited hosting storage.
Recommended Settings by Use Case
Website hero images — aim for under 150KB. Use quality 75–85 for JPEG; this range is imperceptible to most viewers at typical monitor sizes.
Product or gallery images — under 100KB each. Quality 70–80 works well for most photographs.
Thumbnails and icons — under 30KB. Lower quality is acceptable at small display sizes.
Email images — under 100KB per image to keep total email size below provider limits and reduce load time in email clients.
Privacy
Your images are compressed entirely within your browser using the Canvas API. No files are uploaded to any server — everything stays on your device.
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