What is image optimization?

Image optimization is the process of reducing the file size of your images as much as possible without sacrificing visual quality. This is crucial for web performance, SEO, and saving storage space.

Which format should I choose for the web?

WebP is the recommended format for modern websites. It provides significantly better compression than legacy JPEG and PNG formats, meaning your site will load faster.

What quality setting should I use?

For WebP and JPG, a quality setting of 80% offers the best balance. It drastically reduces file size while remaining visually indistinguishable from the original image to the human eye.

How much can image optimization reduce file size?

Converting a JPG to WebP at 80% quality typically reduces file size by 25–50%. Converting to AVIF can reduce it by 50–70% or more, depending on the image content. Results vary by image.

Does image optimization affect SEO?

Yes, positively. Google's Core Web Vitals measure page loading speed, and large images are often the biggest bottleneck. Serving optimized WebP or AVIF images can significantly improve your Largest Contentful Paint (LCP) score.

Can I optimize images without uploading them to a server?

Yes — that is exactly what Converter.Plus does. All compression happens directly in your browser using the Canvas API. Your images are never sent to any server, ensuring complete privacy.

What is the difference between lossy and lossless compression?

Lossy compression (JPG, WebP at less than 100%, AVIF) permanently discards some image data to achieve smaller files. Lossless compression (PNG, WebP at 100%) reduces file size without discarding any data. For most photos, lossy compression at high quality is visually identical to the original.

Can I compress PNG files without converting to another format?

Yes. Choose PNG as the output format on the Image Optimizer. Converter.Plus will re-encode the PNG, applying lossless compression. For even greater size reductions, consider converting to WebP or AVIF.

Image Optimizer — Compress Images Free

Why Optimize Images?

Images usually account for the vast majority of a web page's downloaded bytes. Optimizing images can often yield some of the largest byte savings and performance improvements for your website. Even for personal use, smaller images take less storage, share faster, and upload more quickly.

What kinds of images can be optimized?

Converter.Plus supports compressing JPG, PNG, and WebP images. You can convert them to WebP (recommended for broad compatibility), AVIF (maximum compression), JPG (for photos and print), or PNG (lossless). You can also re-compress existing JPGs or WebPs to reduce their size further.

Better Web Performance

Smaller file sizes mean faster download times. A faster loading website leads to lower bounce rates, higher user engagement, and ultimately better conversion rates. Google's Core Web Vitals — specifically Largest Contentful Paint (LCP) — heavily rewards pages with well-optimized images.

SEO Benefits of Image Optimization

Search engines like Google use page speed as a ranking factor. By serving highly optimized, next-gen formats like WebP or AVIF, you directly improve your site's Core Web Vitals score, potentially boosting your search rankings. Google explicitly recommends serving images in next-gen formats as part of its Lighthouse performance audits.

How to compress images without uploading them

Converter.Plus runs entirely in your browser. When you drop an image file, it is read directly by JavaScript, decoded using the browser's Canvas API, and re-encoded at your chosen quality and format — all without any network request containing your image data. This means:

Your images are never uploaded to any server.
There is no file size limit imposed by a server.
Conversion is instant — no waiting for an upload or download.
It works offline once the page has loaded.

How to optimize images — step by step

Open converter.plus/image-optimizer in any browser.
Drag your JPG, PNG, or WebP files onto the drop zone, or click to select them.
Choose an output format — WebP is recommended for most use cases.
Set quality to 80% for the best size vs. quality balance.
Click Convert and download your optimized images.

Image Optimizer

Drop images to optimize