# AI image upscaler > Make any AI image up to four times bigger and sharper. The AI runs on your own device, so nothing is uploaded, there are no credits, and there is no watermark. Source: https://getoxtro.com/image-upscaler This is an interactive tool. Use it at https://getoxtro.com/image-upscaler; it runs in the browser. ## How to use the image upscaler 1. Drop your image on the board, paste it, or choose a file. 2. Pick 2x or 4x, and choose **Photo** or **Art** to match the picture. 3. Press **Enhance**. The picture becomes a board of tiles, and the AI clears them one at a time. Tap a tile if you want that part done next. 4. Drag the slider to compare the result with a plain stretch, then download it as PNG, JPEG or WebP. ## Why AI images often need upscaling Most AI image tools produce pictures of about one to two megapixels unless you ask for more. That looks fine in a chat window, but it can go soft on a large screen, a banner or a print. A copy saved from a chat or a social app is often smaller again, with compression blocks around the edges. Ordinary enlarging only spreads the same pixels further, so the picture stays blurry. An AI upscaler has learned what sharp edges and textures look like, and it redraws them at the larger size. ## Upscalers for each AI tool The upscaler works on any image, wherever it came from. These pages cover what each tool produces and how to get the best result from it: - [ChatGPT image upscaler](https://getoxtro.com/chatgpt-image-upscaler), including images saved from older DALL-E models - [Nano Banana upscaler](https://getoxtro.com/nano-banana-upscaler), for images from Gemini - [Midjourney upscaler](https://getoxtro.com/midjourney-upscaler) - [Grok image upscaler](https://getoxtro.com/grok-image-upscaler) - [Stable Diffusion upscaler](https://getoxtro.com/stable-diffusion-upscaler) - [Flux upscaler](https://getoxtro.com/flux-upscaler) ## Photo or Art **Photo** suits photographs, realistic renders and most general pictures. **Art** suits anime, cartoons, flat illustration and logos, and it keeps colour areas clean. If you aren't sure, try both, because each run only takes one press. ## What the score and rank mean **Pixels gained** is the real number of pixels added. **Sharpness** compares the crispness of the edges in your result with a plain stretch of the same image, and the rank from C to S comes only from that number. A picture that was already crisp gets a modest rank, which is an honest result. Your total and your badges are kept in this browser, and nowhere else. ## Limits - One image at a time, up to 60 MB. Most computers can make results up to 64 megapixels, and phones or low-memory devices up to about 17 megapixels. - The first run downloads about 9 to 12 MB for the AI model, once. After that your browser keeps a copy. - Computers with a supported graphics card finish much faster. Without one the work runs on your processor, which takes longer but gives the same kind of result. - The AI redraws detail it can't see, so it is making an educated guess. Check faces, hands and small text closely, because they can come out changed. - It enlarges pictures and doesn't remove watermarks. A visible mark in your image stays there. For Gemini's sparkle, use the [Gemini watermark remover](https://getoxtro.com/gemini-watermark-remover) first. ## Frequently asked questions ### Is the AI image upscaler free? Yes. There is no account, no credits and no watermark from us, and there is no daily limit, because your own device does the work. You can use the files however the tool that made the image allows. ### Are my images uploaded? No. The AI model is downloaded to your browser, and your image is processed on your device. It never reaches our server. If you accept analytics in the cookie banner, we count how many images were upscaled, but never their names or contents. ### How much bigger can it make an image? Up to 4x in width and height, which is 16 times the pixels, so a 1024 x 1024 image becomes 4096 x 4096. If there's room on your device, you can send the result through again. ### Can it upscale a ChatGPT or Nano Banana image to 4K? Yes. A 1024 x 1024 image at 4x is 4096 pixels wide, which is wider than the 3840 pixels of 4K. Non-square images reach 4K too: at 4x, anything 960 pixels wide or more will do. ### Does it work on my phone? It works in current mobile browsers, but it is slower, and results are limited to about 17 megapixels. A 1024 x 1024 image at 4x just fits. Close other tabs if it stops part way. ### Is this made by OpenAI or Google? No. Oxtro isn't affiliated with OpenAI, Google, Midjourney, xAI, Stability AI or Black Forest Labs. Their product names are only used to say whose images the tool works with. The upscaling uses the open Real-ESRGAN models.