How to Increase the Resolution of a Picture Free With AI (2026): 6 Easy Methods

Got a small, blurry photo you want to print, use as a wallpaper or post without it looking pixelated? Stretching it in Paint only makes the blur bigger. AI upscalers do something smarter: they redraw the missing detail.

In this guide I show you how to increase the resolution of a picture for free, online, on your phone, in a free desktop app and with local AI models, plus exactly how many pixels you need for prints and screens.

Why Normal Resizing Looks Blurry (and What AI Does)

A photo is a grid of pixels. When you make it bigger in a normal editor, the software has to invent new pixels by averaging the ones next to them, so edges turn soft and blocky.

An AI upscaler has been trained on millions of pairs of low and high resolution images. It recognises hair, skin, text and textures, and draws plausible detail into the new pixels instead of just blending.

Note: AI cannot recover detail that was never captured. It makes a good guess. Faces and fine text can come out slightly different, so check important photos closely.

How Many Pixels Do You Need?

Changing DPI in file properties alone does nothing to quality. What matters is the pixel count. Use this table to find your target, then pick a 2x or 4x upscale that gets you there.

Tip: to find your current size on Windows, right-click the image, choose Properties, then Details. On a Mac, open it in Preview and press Cmd+I.

Which Method Should You Use?

Method 1: Free Online Upscalers

Online tools are the fastest way to fix one picture. The trade-off is that your photo is uploaded to someone else’s server, and free tiers are limited.

Limits come from each tool’s pages as reported in mid to late 2026 and change often, so check before you rely on one.

1. Open the upscaler in your browser.
2. Upload your image. JPG, PNG and WebP are accepted almost everywhere.
3. Pick the scale. 2x is safest; 4x for very small images.
4. Choose a mode if offered. Photo for real pictures, Art or Anime for drawings.
5. Download and compare. Zoom to 100% and check faces and text before you use it.

Warning: do not upload ID cards, private family photos or client work to free online tools unless you have read their privacy policy. Use a local method instead.

For more free web editors, see my free AI photo editor online roundup.

Method 2: Upscayl (Free Desktop App)

Upscayl is my pick for most people. It is free, open source, runs offline on your own graphics card, and has no daily limits or watermarks. The current release is v2.15.

1. Download Upscayl from upscayl.org or its GitHub page. Windows 10+, macOS 12+ and Linux are supported. On Mac you can also run brew install --cask upscayl.
2. Install and open it.
3. Select your image with the “Select Image” button, or turn on Batch Upscayl to do a whole folder.
4. Choose a model. Start with the default general photo model; use a sharper model for illustrations.
5. Set the scale (2x, 3x or 4x) and an output folder.
6. Click Upscayl and wait. A mid-range GPU usually takes seconds per photo.

Note: Upscayl needs a GPU with Vulkan support. Its FAQ says most integrated graphics and CPU-only PCs will not work. Upscayl also sells an optional cloud plan, but the desktop app is free.

Method 3: On Your Phone

• Samsung Galaxy: open the photo in Gallery, tap the three dots and look for Remaster, which sharpens and enhances. My Galaxy AI features guide lists what each phone supports.
• Google Photos: the editor’s enhance and AI editing tools can clean up and sharpen photos; see my Google Photos AI features guide.
• Any phone: the Picsart app and many web upscalers work in a mobile browser.

Phone tools are great for social media sizes. For big prints, a desktop upscaler usually gives more control.

Method 4: Photoshop

1. Classic method: go to Image, Image Size, tick Resample, choose Preserve Details 2.0, then set a 200% or 400% width.
2. Noise slider: raise “Reduce Noise” a little if the result looks gritty.
3. AI method: use Photoshop’s Generative Upscale, powered by Adobe Firefly, for larger jumps. It uses generative credits.

Full details and credit costs are in my Photoshop AI features guide.

Method 5: Real-ESRGAN Command Line

Real-ESRGAN is the free model behind many upscaler apps. The portable NCNN version runs on most GPUs with no Python install.

1. Download the zip for your OS from the Real-ESRGAN GitHub releases: realesrgan-ncnn-vulkan-20220424-windows.zip, -ubuntu.zip or -macos.zip.
2. Extract it to a folder, for example C:\Tools\realesrgan.
3. Open a terminal there and run the command below.

realesrgan-ncnn-vulkan.exe -i photo.jpg -o photo_4x.png -n realesrgan-x4plus -s 4

Use -s 2 or -s 3 for smaller jumps. The Python version adds --face_enhance, which uses GFPGAN to rebuild faces in old photos.

Method 6: ComfyUI (Local, Most Control)

If you already make AI images, ComfyUI can upscale with any model you like and chain it with other steps. New to it? Start with my guide on how to install ComfyUI.

1. Download an upscale model such as 4x-UltraSharp or RealESRGAN_x4plus (.pth or .safetensors).
2. Put it in ComfyUI/models/upscale_models/ and refresh ComfyUI.
3. Add the nodes: Load Image, then Load Upscale Model and Upscale Image (using Model), then Save Image.
4. Want 2x instead of 4x? Add Upscale Image By after the model node with a scale of 0.5.
5. Click Run. The result lands in ComfyUI/output/.

Tip: for AI art, a “hires fix” (upscale, then a light second pass at denoise 0.3 to 0.4) adds real new detail instead of just sharpening. For video, see my SeedVR2 video upscale workflow.

Where every file goes is listed in my ComfyUI model folder cheat sheet.

Which Upscale Model to Pick

Tips for the Best Result

• Start from the original file, not a screenshot or a WhatsApp copy, which are already compressed.
• Upscale 2x twice instead of 4x once if the 4x result looks over-sharpened.
• Save as PNG for editing; export a high-quality JPG or WebP only at the end.
• Crop first. Upscaling just the part you need is faster and uses less VRAM.
• Compare at 100% zoom on eyes, hair and text before printing.

Troubleshooting

Faces look plastic or waxy

The model is too strong. Try a softer model (realesrnet-x4plus), a 2x scale, or blend the result with the original at 50% opacity in an editor.

Upscayl shows an error or a black image

Your GPU probably lacks Vulkan support or has an old driver. Update your graphics driver; on integrated graphics, use an online tool or Real-ESRGAN instead.

“Out of memory” with big images

Use a tile size option (Upscayl and Real-ESRGAN offer one), crop the image, or upscale 2x first. In ComfyUI, the tiled upscale nodes avoid VRAM spikes; see my CUDA out of memory fix.

Text is garbled after upscaling

Upscalers guess letter shapes. Use 2x only, or retype the text in an editor after upscaling the background.

The print still looks soft

Check the pixel size, not the DPI number. Your file should match the pixel targets in the table above for the print size you ordered.

My Take

For one quick photo, a free browser tool is fine. For anything personal, or more than a handful of images, install Upscayl: it is free, private and as good as many paid apps for everyday photos.

If you already run local AI, Real-ESRGAN or ComfyUI give you the most control, especially for AI art where a second pass adds genuine detail.

FAQ

How do I increase the resolution of a picture for free?

Use a free AI upscaler such as Upscayl on your PC, or a browser tool like waifu2x. Both can make an image 2x to 4x larger with sharper detail.

Does changing DPI increase image quality?

No. DPI is only a print setting. Quality depends on the number of pixels, so you need to upscale to add pixels.

What is the best free AI image upscaler?

For most people, Upscayl: it is open source, unlimited and offline. Online, waifu2x is free with no sign-up but has size limits.

Can I upscale an image without losing quality?

AI upscaling keeps photos looking sharp at 2x to 4x, but it guesses new detail. Small faces and text can change slightly, so always check the result.

Can I upscale images on my phone?

Yes. Samsung Gallery’s Remaster tool, Google Photos editing tools and apps like Picsart can enhance and enlarge photos on a phone.

How big can I print a 12 megapixel photo?

A 12 MP photo (about 4,000 x 3,000 px) prints sharply at about 13 x 10 inches at 300 PPI. Upscale it 2x for larger prints.

Is it safe to use online image upscalers?

For ordinary photos, generally yes, but your image is uploaded to their servers. Use an offline tool like Upscayl for private pictures.

Sources

• Upscayl on GitHub
• xinntao/Real-ESRGAN on GitHub
• Atlas Cloud: Best free image upscaler 2026 (vendor limits, Sept 2026)
• imgmend: Best free AI image upscalers online 2026
• ComfyUI docs: model folders