Does it follow my lines?

Yes. The prompt keeps the composition, shapes and proportions as drawn. The clearer the lines, the closer the result.

Yes. Every AI image tool here is free to use, with or without an account, and there is no watermark. You get 10 images a day without signing in and 30 a day with a free SandBase account. The allowance resets at midnight UTC.

Are my photos stored?

No. Your photo is sent to the image model for this one request and the result comes straight back to your browser. Nothing is saved to a gallery. A copy of the result is kept in a short-lived cache for 24 hours so that pressing the button twice does not use two runs.

Does it work on my phone?

Yes. The tools work in any modern mobile browser. Tap the upload area to pick a photo or take one with the camera, then download the result to your photos.

Free · no sign-up

Free sketch to image converter

Draw it rough, get it finished: upload a pencil sketch or a doodle and the AI adds color, materials, light and detail while keeping your shapes and layout.

100% free
No sign-up
No watermark
Works on phone

Sample result

Example

BeforeAfter

A pencil sketch of a cottage turned into a colorful illustration.

How to use the Sketch to Image

Three steps, on a computer or a phone.

1. Upload a photoDrop, paste or pick a JPG, PNG, WebP or HEIC photo. On a phone you can take one with the camera.
2. Choose your optionsSet the options, then press the button. It takes about 20 seconds.
3. Compare and downloadDrag the slider to compare with the original, then download the result.

What people use it for

Concept artQuick explorations from thumbnail sketches.
Kids' drawingsSee a child's drawing as a finished picture.
Design draftsProduct and scene ideas from a few lines.

More free AI image tools

All free, no sign-up, no watermark.

Need more control? Use the API

This tool runs on the SandBase image API. The API gives you every setting the free tool fixes for you.

Higher quality and sizequality=high, sizes up to 2K, and transparent backgrounds in one call.
Your own promptChange the template below, add reference images, or batch hundreds of images from your code or Agent.
No daily limitPay per image from one SandBase balance, with the same key for 2,000+ models and APIs.

API reference Image models and prices Get an API key

curl https://api.sandbase.ai/v1/images/edits \
  -H "Authorization: Bearer $SANDBASE_API_KEY" \
  -F "model=gpt-image-2.6-flare" \
  -F "[email protected]" \
  -F "quality=high" \
  -F "size=2048x2048" \
  -F 'prompt=Turn this sketch into a finished colorful illustration. Keep the composition, shapes and proportions exactly as drawn; a…'

The free tool uses this prompt template with your choices filled in.

Frequently asked questions

Does it follow my lines?: Yes. The prompt keeps the composition, shapes and proportions as drawn. The clearer the lines, the closer the result.
Is it really free?: Yes. Every AI image tool here is free to use, with or without an account, and there is no watermark. You get 10 images a day without signing in and 30 a day with a free SandBase account. The allowance resets at midnight UTC.
Are my photos stored?: No. Your photo is sent to the image model for this one request and the result comes straight back to your browser. Nothing is saved to a gallery. A copy of the result is kept in a short-lived cache for 24 hours so that pressing the button twice does not use two runs.
Does it work on my phone?: Yes. The tools work in any modern mobile browser. Tap the upload area to pick a photo or take one with the camera, then download the result to your photos.