All tools

Annotate an image online

Open any photo, diagram or screenshot and mark it up: boxes, arrows, text notes, numbered callouts, highlights and blur. It all runs in your browser, so the image never leaves your device.

How it works

  1. 1

    Open the image

    Choose a file, drop it on the editor or paste it with Ctrl+V (⌘V). PNG, JPG, WebP and GIF all work, at full resolution.

  2. 2

    Add your notes

    Box (R) or circle (E) the area, point with an arrow (A), type a note (T), number the parts (N) or blur anything private (B).

  3. 3

    Save or share

    Download a PNG, JPG or WebP, copy it to the clipboard, or share it straight from your phone.

Annotating photos and diagrams, not just screenshots

  • Photos are busy, so keep the white Outline on: it keeps a box or arrow visible over grass, skin or sky.
  • Number the parts (N) and explain them in the message, instead of crowding the picture with long text.
  • Turn on Label (with the Text tool) for text on a solid background. It reads on any photo.
  • Crop (C) first so the important part fills the frame. Annotations scale with the image, so they stay sharp.
  • Blur faces, number plates and addresses before sharing a photo publicly. For anything secret, use Redact (D), the solid box.

Questions people ask

How do I annotate an image online for free?
Open the image in the editor above, pick a tool (box, arrow, text, numbers, highlighter or blur) and draw on it. Then download or copy the result. It’s free, with no account and no watermark.
Is this the same as an image annotation tool for machine learning?
No. Tools like CVAT or Label Studio draw labelled bounding boxes to train AI models and export them as data files. AnnotateFast marks up a picture for people to read and exports an image.
Can I annotate a photo on my phone?
Yes. Tap Choose screenshot, pick a photo from your library and draw with your finger. On phones that support it, Share sends the finished image straight to another app.
Are my images uploaded?
No. The image opens in a canvas in your browser and is exported there. Nothing is sent to a server.
Can I add text notes to an image?
Yes. Pick Text (T), click where the note should go and type. Turn on Label for a filled background that stays readable on busy photos. Double-click a note later to edit it.