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How to Colorize a Black and White Photo with AI (Free)

Got an old family photo, a historical picture, or any black-and-white image you wish you could see in color? Here's how to bring it to life with AI, right in your browser — no software, no upload to a third-party server.

Steps

  1. Open Stelluna's AI Image Upscaler at stelluna.io/image-upscaler and upload your black and white photo — JPG, PNG, or WEBP, up to 15MB.
  2. Check the "Colorize black & white photo" box. The button will change to "Colorize, Upscale & Sharpen."
  3. Click the button. The AI models download to your browser the first time you use them (one-time only) — your photo is colorized first, then upscaled 4x.
  4. Download the result — colorized and enlarged in a single step.

Ready to try it? Free, instant, your photo never leaves your device.

Open AI Photo Colorizer

How does AI colorization work?

The AI model (DDColor) was trained on millions of color photographs to learn what colors typically belong to different objects, textures, and scenes — skin tones, sky, foliage, fabric. It looks only at the brightness (luminance) information in your black-and-white photo and predicts the missing color (chrominance) information, then blends the two together. Because the sharpness and detail come entirely from your original photo's resolution and only the color is generated, the result stays crisp — not blurry or over-smoothed like some simpler colorization tools.

FAQ

Is it free?

Yes — no account, no watermark, no limit on how many photos you colorize.

Does my photo get uploaded anywhere?

No. The AI model runs entirely inside your browser using WebGPU or WebAssembly — the photo is never sent to a server.

Will the colors be historically accurate?

The AI makes its best plausible guess based on patterns learned from color photos — skin, sky, and common materials are usually convincing, but it can't know the exact original color of, say, a specific dress or car. Think of it as a realistic reconstruction, not a historical record.

Is there a size limit?

Input is capped at 15MB. Colorization happens at up to 1600px (color is predicted at 512px internally, detail preserved from your photo), then that result is automatically upscaled 4x, so your final download is significantly larger than the original.

Can I colorize without upscaling, or upscale without colorizing?

Yes — leave the "Colorize" checkbox unchecked to just upscale and sharpen a photo as-is (color or black and white). Check it to colorize first and then upscale, all in one click.

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