How to Compress Images for a Website Without Losing Quality

Large photos are the most common reason a website feels slow. A picture straight from a phone is often 3 to 6 MB, while the same picture shown in a blog post rarely needs to be more than 150–300 KB. The good news: you can usually cut the size by well over half without anyone noticing, as long as you do it in the right order.

Why image size matters

Every image on a page has to be downloaded before it appears. On a phone with a weak connection, a 5 MB photo can take several seconds, and visitors leave before it arrives. Smaller images also mean less data used by your visitors and less storage on your hosting.

Search engines notice too. Page speed is part of how Google measures the experience of a page, and oversized images are one of the first things speed tests point out.

Step 1: Resize to the size you actually show

Compression shrinks the file, but resizing removes pixels you never needed. If your blog column is 800 pixels wide, an image 4,000 pixels wide wastes most of its data.

A good rule of thumb:

• Full-width banners: around 1,600–2,000 pixels wide.
• Images inside an article: about twice the column width, so they stay sharp on high-resolution screens (for an 800 px column, 1,600 px).
• Thumbnails and cards: 400–600 pixels wide.

Use the Image Resizer to set a width; leave the height empty so the picture keeps its shape. You can resize many images at once and download them as a ZIP.

Step 2: Choose the right format

• JPG is best for photos. It is understood by every browser, app and email program.
• PNG is best for screenshots, logos and anything with sharp edges or transparency. It is lossless, which makes photo files large.
• WebP and AVIF are newer formats made for the web. They are usually smaller than JPG at the same quality and support transparency. All current major browsers show them.

If a photo was saved as PNG, converting it to JPG or WebP with the Image Converter often makes it several times smaller on its own.

Step 3: Compress with a quality setting

Open the Image Compressor, add your images and start with a quality around 75. Phone photos often shrink by 50–80% at that setting without a visible difference. Compare the before and after at full size, especially in areas with fine detail such as hair, grass or text. If you can see blocks or smudges, raise the quality a little.

If a form or a platform demands a maximum size, use the target file size option instead: enter, for example, 200 KB and the tool finds the best quality that fits. When quality alone isn't enough for a very large photo, it also reduces the width and height until the file fits.

Common mistakes

• Compressing the same JPG again and again. Each save loses a little more detail. Keep your originals and always compress from them.
• Compressing before resizing. Resize first, then compress; the result is smaller and sharper.
• Using PNG for photos. Unless you need transparency, a photo belongs in JPG, WebP or AVIF.
• Forgetting the dimensions in your HTML. Adding width and height to image tags stops the page from jumping while images load.

Keep your photos private

Many online compressors upload your pictures to their servers. The tools linked here run entirely in your browser: your images are processed on your own device and never sent anywhere, which matters for photos of people, documents or unreleased work.

Quick checklist

1. Resize to about twice the display width.
2. Pick JPG or WebP for photos, PNG for graphics.
3. Compress at quality 70–80 and compare.
4. Keep the originals.

Do this once for every new image and your pages will stay fast as your site grows.