AI generators often output images that are fine for a screen but too small for a print, a banner or a large hero image. Upscaling can help, but it is worth understanding what it does and what it cannot.
Here is how to work out the size you need and the right way to enlarge.
Key Takeaway: Calculate the pixels you need first. Upscale in one step from the original, and expect interpolation to sharpen, not to add real new detail.
Step 1: Work Out the Pixels You Need
For print, multiply the print size in inches by the DPI. At 300 DPI, a 4 x 6 inch print needs 1200 x 1800 pixels, and an 8 x 10 needs 2400 x 3000. For screens, you need about the display size, up to roughly twice that for high-density displays. More on DPI in DPI vs PPI explained.
Step 2: Choose the Right Kind of Upscaler
| Type | What it does | Best for |
|---|---|---|
| Interpolation (e.g. Lanczos) | Fills in new pixels from neighbors and sharpens edges | 2x to 4x, keeping the image faithful |
| Generative AI upscaler | Predicts and invents plausible new detail | Big jumps, but may alter faces and textures |
The TinyPNG Now Upscale tool uses Lanczos-style interpolation with mild sharpening, so it stays true to your image and runs in your browser. It does not generate new detail. For the algorithm differences, read the upscaling guide.
Step 3: Upscale, Check, and Compress
- Upscale once from the original with the Upscale tool. Avoid repeated enlargements, which stack softness.
- Zoom in to 100 percent and check faces, hands, text and edges.
- Save as PNG for print masters, or compress a web copy as WebP or JPG with the compressor.
Reality check: No upscaler can fully rescue a very small or blurry image. If you can, regenerate or export at a higher resolution from the AI tool itself.
Frequently Asked Questions
How do I upscale an AI-generated image?
Decide the pixel size you need, then enlarge the original once with an upscaler. For 2x to 4x, interpolation works well; for bigger jumps, a generative upscaler may add detail.
How many pixels do I need to print an image?
Multiply the print size in inches by 300 for good quality. A 4 x 6 inch print needs about 1200 x 1800 pixels.
Does the TinyPNG Now upscaler use generative AI?
No. It uses high-quality Lanczos-style interpolation with mild sharpening, running in your browser. It enlarges faithfully rather than inventing new detail.
Why does my upscaled AI image look soft?
Interpolation cannot add real detail. Upscale once, from the original, and consider regenerating at a higher resolution if you need a big print.
Is it safe to upscale images online?
With TinyPNG Now the upscaling happens in your browser, so your image is not uploaded. Other tools may upload files, so check their privacy policies.
Summary: Calculate the pixels you need, upscale once from the original, and check the result at 100 percent. Use the free Upscale tool for faithful 2x to 4x enlargements.