Compress Images — Free & No Upload

Why you should compress images

On most websites, images account for the largest share of everything a visitor has to download. A single untouched photo from a modern phone camera can weigh 5 to 12 megabytes. Push files like that straight into a blog post, a product listing or a landing page and you pay for it in several currencies at once: slower load times, weaker search rankings, higher bounce rates, and bandwidth bills that grow with your traffic.

Compressing an image solves exactly that problem. Compression reduces file size by discarding information the human eye barely registers in the first place — subtle colour transitions, high-frequency noise, detail hidden in shadows. Combine that with a modern codec and the numbers get dramatic: an 8 MB photo routinely comes out at 250–400 KB and still looks, to any normal viewer, identical to the original.

There is a hard business case behind this too. Google treats loading performance as a ranking signal through Core Web Vitals, and the metric images hurt most is Largest Contentful Paint — usually the hero image at the top of your page. If that image is a 4 MB JPEG, LCP suffers, and so does your position in search results. Studies across e-commerce consistently show conversion rates falling as load time climbs past two or three seconds. Compressed images are one of the cheapest, fastest wins available: no redesign, no re-platforming, just smaller files.

The same logic applies well beyond websites. Smaller files upload faster to a CMS, attach cleanly to emails that would otherwise bounce off size limits, sync quicker to cloud storage, and take up far less space on a laptop that is running out of room.

WebP vs. AVIF vs. JPEG vs. PNG — which format should you use?

Format choice matters more than almost any other setting. It determines both how small your file gets and how good it looks at that size. Here is an honest breakdown of the four formats this tool supports.

WebP — the best all-round choice for the web

Developed by Google and now supported by every current browser, WebP has become the de facto standard for web imagery. At matching visual quality it typically produces files 25–35% smaller than JPEG, and unlike JPEG it supports transparency, so it can replace PNG for many interface graphics as well. It encodes fast, degrades gracefully, and there is effectively no compatibility risk left in 2024 and beyond. For the vast majority of photos and graphics on a website, WebP is simply the right answer — which is why it is the default here.

AVIF — maximum compression, at a price

AVIF is built on the AV1 video codec and compresses more aggressively than anything else in this list, often another 20–30% smaller than WebP at comparable quality. It also handles gradients and flat colour areas remarkably well, where JPEG tends to show banding. The trade-offs are real, though: encoding is noticeably slower, and not every browser can create AVIF files even if it can display them. This tool only offers the AVIF option when your browser actually supports encoding it. Choose AVIF when you want the absolute smallest file and you are serving it with a WebP or JPEG fallback.

JPEG — the universal standard for photographs

JPEG has been around since the early 1990s and works literally everywhere: every browser, every operating system, every photo frame, every ancient content management system. For photographs without transparency it remains perfectly solid. If maximum compatibility is the priority — emailing files to a client, uploading to a platform with restrictive format rules, feeding an older system — JPEG is the safe bet. For a modern website, WebP will give you the same picture in a smaller file.

PNG — for logos, screenshots and transparency

PNG is lossless: it reproduces every pixel exactly as it was. That makes it ideal for logos, icons, UI screenshots, diagrams, and anything with hard edges, flat colour or a transparent background — the kinds of images where lossy compression produces ugly halos and smearing. The cost is file size. For photographs PNG is almost always the wrong choice; WebP or JPEG will beat it by an order of magnitude. Note that when you select PNG here the quality slider has no effect, because lossless compression has no quality dial to turn.

How to compress images — step by step

Using the tool above takes a few seconds:

1. Add your images: drag them onto the drop area, click choose files to pick them from your device, or paste an image straight from your clipboard with Ctrl + V (Cmd + V on a Mac).
2. Pick an output format: WebP, JPEG, PNG or AVIF — or select Original to keep the format you started with and simply recompress it.
3. Set the quality: the slider controls the balance between file size and fidelity. 75–85% is an excellent compromise for most photographs; lower it further for thumbnails and decorative images.
4. Resize if needed: enter a maximum width to scale oversized images down to sensible web dimensions. A 6000-pixel-wide camera photo displayed in a 1200-pixel column is wasting most of its bytes — capping the width often saves more than compression alone.
5. Download: grab each result individually, or download everything at once as a single ZIP archive.

Change a setting at any point and every image is recompressed automatically from the original, so you can experiment freely without degrading anything. Compression is never applied on top of compression here — each pass starts from the file you dropped in.

Privacy: your images never leave your device

Most online image compressors work the same way: you upload your files to somebody else's server, they are processed there, and the results come back to you. You have no way of knowing how long those files are retained, who can access them, or whether they are used for anything beyond the task you asked for. For sensitive material — identity documents, medical scans, internal screenshots, private photos — that is a genuine risk, not a theoretical one.

This tool works fundamentally differently. All compression runs locally in your browser: each image is redrawn onto an HTML5 canvas and re-encoded using the native codecs already built into your browser. There is no upload, no server-side processing and no storage. Your files stay entirely on your machine. You can even disconnect from the internet once the page has loaded and everything still works. Here, privacy is not a marketing promise — it is simply how the architecture works.

Frequently asked questions

Compression engine based on NyxCompress — open source and fully client-side.