Reduce image file sizes by 30–80% without visible quality degradation — directly in your browser, without uploading anything to a server. Drop a JPEG, PNG, or WebP file and get a compressed version in seconds. No account needed, no file size limits, completely free.
WebAssembly and the Canvas API power the compression engine, so your photos, product images, screenshots, and design exports never leave your device. That's the core difference from tools like TinyPNG, Compressor.io, and Optimizilla — those upload your files to their servers, while this one keeps everything local.
How to Compress an Image Online
Getting a smaller file takes three steps:
- Upload your image — drag and drop a JPEG, PNG, WebP, or GIF onto the drop zone, or click to browse your files. No size limit.
- Choose your compression settings — for JPEG and WebP, use the quality slider (default: 80%). For PNG, choose between lossless re-encoding (no quality loss) or converting to WebP for larger reductions.
- Download the result — click "Compress Image," then "Download" to save the compressed file.
The side-by-side comparison shows the original versus the compressed image, with the exact file size and percentage reduction displayed.
Lossy vs. Lossless Image Compression
Choosing the right compression type makes a significant difference in results:
Lossless compression reorganizes image data more efficiently without discarding anything. The result is bit-for-bit identical to the original. File size reduction is typically 5–30%. Best for: PNG logos, screenshots with text, images that will be edited later, anything where pixel-perfect accuracy matters.
Lossy compression permanently removes image data deemed least perceptible to the human eye. At quality settings of 75–85%, the result is visually indistinguishable from the original at normal viewing sizes, while file size drops by 30–70%. Best for: JPEG photos, product images, blog images, hero banners — anywhere the difference can't be seen.
| Type | Reduction | Quality Impact | Best For |
|---|---|---|---|
| Lossless (PNG re-encode) | 5–30% | None | Logos, screenshots, icons |
| Lossy JPEG at 80% | 30–60% | Imperceptible | Photos, blog images |
| PNG → WebP at 85% | 50–80% | Minimal | Web assets, product photos |
Why Image Compression Matters for Web Performance
Images account for 40–44% of a typical webpage's total weight. Uncompressed images are the single most common cause of slow page load speeds and poor Core Web Vitals scores.
LCP (Largest Contentful Paint) is the Core Web Vitals metric most affected by image compression. It measures how quickly the largest visible element — usually a hero image — loads on screen. Google requires LCP under 2.5 seconds for a "Good" score. A hero image that's 3 MB can easily push LCP above 4–5 seconds on a mobile connection. Compressed to 200 KB with WebP, that same image can achieve LCP under 1.5 seconds.
Practical file size targets for website images:
- Hero/banner images: under 200 KB (ideally under 100 KB with WebP)
- Blog in-content images: under 100 KB
- Product thumbnails: under 30 KB
- Full-size product photos: under 300 KB
Common Use Cases for Image Compression
- Web developers and SEO professionals: optimize images before uploading to improve PageSpeed scores, Core Web Vitals, and Google rankings.
- E-commerce stores: compress product photos to reduce page weight without sacrificing visual quality on listing pages.
- Bloggers and CMS users: shrink images before uploading to WordPress, Ghost, or Webflow to stay within media library limits.
- Email marketing: reduce attached or embedded images to stay under size limits for Gmail, Outlook, and email service providers.
- Social media: compress before uploading to Instagram, Twitter/X, or LinkedIn to avoid platform recompression artifacts.
- Privacy-sensitive work: medical images, legal documents, client photos — compress without sending files to a third-party server.
Frequently Asked Questions
Is my image uploaded to a server when I compress it?
No. This compressor runs entirely in your browser using WebAssembly and the Canvas API. Your files — including private photos, medical images, client documents, and corporate assets — are never transmitted to any server, stored, or seen by anyone. This makes it fundamentally safer than TinyPNG, Compressor.io, and other server-based tools for sensitive images.
Does compressing an image reduce its quality?
It depends on the compression type. Lossless compression (used for PNG re-encoding) reorganizes data more efficiently without removing any — quality is identical to the original. Lossy compression (used for JPEG and WebP output) removes data deemed imperceptible. At 75–85% quality, the difference is invisible at normal viewing sizes. Quality artifacts only become visible at settings below 60%, which are not suitable for most uses.
How do I compress an image to under 100 KB?
Use the quality slider and set it to 70–80%. Most JPEG photos taken on a smartphone (typically 2–4 MP at this quality) compress well under 100 KB. For even smaller results, enable "Convert to WebP" — WebP at the same quality setting is 25–35% smaller than JPEG. GIFs and PNGs with photos are best converted to WebP.
What is the difference between this tool and TinyPNG?
TinyPNG is excellent but uploads your images to its servers (a privacy concern), limits free users to 20 images per month and 5 MB per file, and does not support WebP output with a quality slider. This tool processes everything in your browser, has no file count or size limits, is free with no signup, and lets you control output quality. The tradeoff: TinyPNG's lossy PNG quantization can sometimes achieve smaller PNG files than lossless re-encoding.
What is the best image format for web in 2025?
WebP offers the best balance of compression, quality, and browser support (~97% as of 2025). It's 25–35% smaller than JPEG at equivalent quality and supports transparency. AVIF achieves 20–50% better compression than WebP, but encoding is slower. For maximum compatibility, use WebP as your primary format and provide JPEG as a fallback via the <picture> element.
Why is my compressed PNG larger than the original?
This can happen when the original PNG was already well-optimized or used lossy quantization (tools like TinyPNG apply lossy PNG compression). Lossless re-encoding cannot make an already-optimal file smaller. In this case, switch to "Convert to WebP" mode — WebP lossy will achieve significant size reductions even on already-compressed PNGs.
If you also need to change image dimensions, try the Image Resizer — it resizes by pixel or percentage directly in your browser, with the same privacy guarantees.
Resources
- Google Web.dev — Optimize Images — Google's guide to image optimization for Core Web Vitals, covering formats, compression, and lazy loading.
- WebP Compression Study — Google — Technical benchmark comparing WebP vs JPEG compression ratios across 900,000 images.
