Guide
How to annotate a screenshotand explain it to AI
A few boxes and short notes turn a busy screenshot into a clear request. Here's how to do it on a Mac, and how to write notes that an AI chat can follow first time.
The built-in way
Every Mac comes with Markup, which opens from a screenshot or from Preview.
Take the screenshot
Press Shift-Command-4 and drag around the area, or press Shift-Command-5 for more choices. Click the thumbnail that appears in the corner to open Markup.
Draw your marks
Click Shapes to add a rectangle, oval or arrow. The loupe magnifies a small detail. Use Border Color to make each mark stand out.
Add text, then Done
Click the Text tool, type your note and drag the box next to its mark. Click Done, then copy, share or drag the picture where it needs to go.
Fine for one mark, slow for five
Each text box is placed and sized by hand. Numbering is up to you, and notes drawn over the picture can cover the very thing you're pointing at. It works, but a list of changes takes a while.
Notes an AI can follow
However you mark it, these habits get you the right answer sooner.
One number per change
Give every mark a number and a note with the same number. Ask for five things and each one stays separate, so none gets skipped.
Say what you want
“Should say Join now” beats “this is wrong”. Name the result you're after, not just the problem.
Show only what matters
Crop away the rest of the screen. Less to look at means less to misread, and fewer private details sent by accident.
Faster with Hyduri Capture
Hyduri Capture was made for exactly this. Every box gets a number, every number gets a row, and the cursor is already waiting for your note.
Click the camera
Your whole screen is captured and you're ready to mark. Hover over the camera instead to pick one screen or window.
Drag a box and type
Mark is the default. Drag around the thing you mean and a numbered row opens with the cursor ready. Type your note. The X on a row removes that box.
Send to Chat
Click in ChatGPT or any chat and press Send to Chat. The picture and its numbered notes arrive together in one message.
Point, find and tidy
It names what you click
Point at a button, image or text and it lights up. Click it, and its name is already in your note, like Button “Sign up today”.
Search the picture
Type words, or a kind of thing like “login button” or “images”, in the Find field. Every match on the captured picture lights up, ready to mark.
Steps in reading order
Organise Steps puts your notes in reading order, renumbers them and cleans the wording. It won't rewrite what you said.
A sheet of just the marks
Crop into Tiles cuts every box into one clean sheet, each tile with its number and note, which you can still change. That sheet is what gets sent.
Your kind of notes
Show notes as a List, Sticky Notes or Glass Bubbles, and pick your highlight colour. Add a comment about the whole picture too.
Turn it into a how-to
Press Share and choose Steps Document (PDF). Each picture becomes one numbered page that anyone can follow.
Prefer your screen to stay live while you write? Choose Mini Panel as your default in Settings. It docks to the side while your screen stays live, instead of freezing it the way Mark on Screen does.
Good to know
Why doesn't Select name the buttons I point at?
It needs Accessibility allowed in System Settings. Without it, the app still finds text and shapes in the picture, but not real button names. Some apps don't share these details.
Can I change a picture I've already marked?
Yes. Point at it in Recent and press Edit. Pictures you marked in Hyduri Capture open with their marks and comments ready to change, and you can add new ones.
Say it once, get it right
Hyduri Capture is $29 once for up to two devices, with no subscription. Every feature is free for 7 days. It needs macOS 14 or newer.
More guides: Send a screenshot to ChatGPT · Blur private details in a screenshot · Record your screen with captions