Image Compressor

An image compressor makes photos smaller in file size without making them look noticeably worse, so your pages load faster and your uploads fit form limits. Our free tool compresses JPG, PNG and WebP images entirely in your browser: nothing is uploaded to our servers. Set a quality level, optionally cap the width, choose whether to keep the original format or switch to JPEG or WebP, and compress up to 20 images at once. You see the original size, the new size and the percentage saved for every file, then download each one or all of them as a ZIP.

How to use the Image compressor

1. 1 Add your imagesDrop up to 20 JPG, PNG or WebP files onto the tool, or pick them from your device. They are read locally by your browser and never leave your computer or phone.
2. 2 Choose a quality levelMove the quality slider between 10 and 100. Around 70 to 80 is a sensible starting point for website photos: much smaller files with little visible difference.
3. 3 Set a maximum width if neededIf your photos come straight from a phone or camera, enter a maximum width such as 1600 or 2000 pixels. Images wider than that are scaled down, which often saves more than quality alone.
4. 4 Pick the output formatKeep the original format, or convert to JPEG or WebP. For PNG photos and screenshots, the tool suggests WebP because re-saving a PNG as PNG usually saves very little.
5. 5 Compare and downloadCheck the original size, new size and percentage saved for each image. Download files one by one, or download everything as a single ZIP.

Why image size matters for your website

Images are usually the heaviest part of a web page. A single unedited phone photo can be 3 to 6 MB, which is more than the rest of a typical small business page put together. On a mobile connection in a rural part of the UK, or on a busy train, that difference is the gap between a page that appears instantly and one that visitors give up on.

Image weight also feeds directly into Core Web Vitals, the page experience measures Google uses. Largest Contentful Paint (LCP) records how long the biggest visible element takes to render, and on most homepages and product pages that element is a hero image or banner. Google treats an LCP of 2.5 seconds or less as good. A 4 MB hero image makes that hard to hit on mobile, while the same image compressed to 200 KB usually gets you there with room to spare.

Smaller images also use less of your hosting bandwidth and storage, back up faster, and are kinder to visitors on limited mobile data plans.

How lossy compression and the quality slider work

JPEG and WebP use lossy compression. They throw away fine detail that the eye is not very sensitive to, such as subtle colour variation in a sky, and store the rest efficiently. The quality slider controls how much is thrown away. At 100 almost nothing is discarded and files stay large. At 10 files are tiny but you will see blocky patches, smeared edges and colour banding.

The relationship is not linear. Dropping from 100 to 85 often halves the file size with no difference anyone could spot. Dropping from 85 to 70 saves a useful amount more with only minor softening on close inspection. Below about 50, artefacts become obvious on photos with lots of fine detail, such as foliage, fabric or hair. The best setting depends on the image, which is why the tool shows the new size straight away so you can try a couple of values.

PNG is different. It is a lossless format, so re-encoding a PNG as PNG keeps every pixel and saves very little. That is why the tool suggests WebP when you compress PNG files: WebP can keep transparency and still produce files far smaller than PNG, especially for photos and screenshots.

How to compress an image to 100 KB, 200 KB or 1 MB

Plenty of forms set hard limits: job application portals, council and HMRC-style uploads, marketplace listings, email attachments and website builders. If you need to get under a specific size, combine the two levers the tool gives you: dimensions and quality.

Start with the maximum width, because pixel count has the biggest effect. A 4000 pixel wide photo has roughly four times as many pixels as a 2000 pixel one. Then lower the quality step by step and watch the new size until it falls under your target. If you reach a quality of 50 and the file is still too big, reduce the width further rather than pushing quality lower, as a smaller sharp image looks better than a larger blotchy one.

• Under 100 KB: try a maximum width of 1000 to 1200 pixels and quality around 60 to 70, as JPEG or WebP.
• Under 200 KB: try 1600 pixels wide at quality 70 to 75. This also suits most website hero images.
• Under 1 MB: usually achievable at full phone resolution with quality around 75 to 80.
• Passport-style or ID photos for official forms often have their own pixel requirements, so check those first and only compress after resizing.

JPEG, WebP or PNG: which output to choose

Choose WebP for website images whenever you can. All current versions of Chrome, Edge, Firefox and Safari support it, and at similar visual quality it is typically noticeably smaller than JPEG. It also supports transparency, so it can replace PNG for logos and cut-out product shots.

Choose JPEG when you are sending the file somewhere that may not accept WebP, such as an older content management system, an email client, a print shop or an upload form that lists only JPG and PNG. JPEG works everywhere.

Keep the original format when a system specifically requires it, or when a PNG contains sharp text, line art or a flat-colour graphic and you need to keep it lossless. For those, the savings will be small, and that is expected.

Your images stay on your device

Many free online compressors upload your files to a remote server, process them there and keep copies for an unknown period. Ours does the work inside your browser using the browser's own image tools. The files are never sent to MakeItFlow, so there is nothing for us to store, share or lose.

That matters if you are compressing photos of staff, customers, children at a school event, signed documents or unreleased product shots. Under UK GDPR, photos of identifiable people are personal data, and keeping them on your own device avoids handing them to a third-party processor at all. Because everything runs locally, the tool also keeps working on a slow connection once the page has loaded, and large batches are limited only by your device's memory.

Compression is one part of fast-loading images

A well-compressed file is the biggest single win, but how the image is placed on the page matters too. Serve images at roughly the size they are displayed: a 3000 pixel wide photo shown in a 600 pixel column wastes most of its data. Our image resizer is useful for producing exact sizes, and the srcset attribute lets browsers pick a smaller version on phones.

Add width and height attributes to every img tag so the browser reserves space before the image arrives. This prevents layout shift, which is measured by another Core Web Vital, Cumulative Layout Shift. Add loading="lazy" to images further down the page, but not to the main hero image, as lazy loading the LCP element delays it.

To see where your site stands, run our free website audit. It checks page speed and flags oversized images alongside SEO, security and email issues, so you can see the effect of compressing your images on the pages that matter.

Examples you can copy

Website hero / banner      max width 1920-2000 px, WebP, quality 75
Blog or article image      max width 1200-1600 px, WebP, quality 75
Product photo              max width 1200-1600 px, WebP or JPEG, quality 80
Email attachment           max width 1600 px, JPEG, quality 70
Form with 100 KB limit     max width 1000-1200 px, JPEG, quality 60-70
Screenshot (PNG)           keep width, WebP, quality 80-90

magick photo.jpg -resize "1600x>" -quality 75 -strip photo-web.jpg

magick photo.jpg -resize "1200x>" -define jpeg:extent=100kb photo-100kb.jpg

cwebp -q 75 photo.png -o photo.webp

Common mistakes to avoid

Frequently asked questions