How to Compress an Image Online
Large image files slow down websites, fill up storage, and make emails bounce. This tool re-encodes your JPG or PNG at an adjustable quality level so you can shrink the file size while keeping it visually sharp.
Steps
- Upload one or more images.
- Drag the quality slider — lower values mean smaller files but more compression artifacts.
- Click "Compress Images" and download the result, along with a before/after size comparison.
Worked example: A 3.2 MB JPG photo compressed at 80% quality typically comes out around 900 KB — a 72% reduction — with the drop in sharpness barely visible on screen. Push the slider down to 50% and the same photo might shrink to 400 KB, useful for a thumbnail but noticeably softer if viewed at full size.
Choosing the Right Quality Level
For most photos, 70-85% quality gives a large size reduction with almost no visible difference. Go lower (40-60%) for thumbnails or background images where fine detail doesn't matter as much. Avoid compressing an already-compressed JPG too aggressively, since quality loss compounds each time.
Quality Setting Guide
| Quality | Typical Size Reduction | Best For |
|---|---|---|
| 90-100% | 10-30% | Print, professional photography |
| 70-85% | 50-75% | Website hero images, blog photos |
| 40-60% | 75-90% | Thumbnails, background images |
Common Uses
Website owners compress hero images to improve page load speed and Core Web Vitals scores. Job seekers shrink a scanned resume photo so it fits an application form's file size limit. Because compression happens locally in your browser using the Canvas API, your images are never uploaded to a server.
Frequently Asked Questions
What quality setting should I use?
70-85% is a good balance of size and visual quality for most photos.
Does this work with PNG files?
Yes, both JPG and PNG are supported; PNG compression uses the same quality slider though PNG is lossless internally so gains vary.
Is there a file size limit?
The limit depends on your device's available memory, but typical photos of a few MB each work fine, including in batches.
Are my images uploaded anywhere?
No, all compression happens locally in your browser.
Will I lose quality every time I compress the same image?
Yes, JPG compression is lossy, so repeatedly compressing an already-compressed file causes cumulative quality loss. Always compress from the original, highest-quality source.