How to annotate a screenshot on iPhone
The whole loop on iPhone and iPad: get the image into an editor, cover what should not travel, point at what matters, crop, and get it back out. Including the two things the built-in Markup will not do for you.
You have a screenshot on your phone and something on it needs to change before you send it. Usually two things at once: something has to be covered, and something has to be pointed at. This page walks the whole loop — capture, cover, point, crop, send — with the built-in tools first, because for a large share of screenshots they are genuinely enough, and then the two specific places where they run out.
The short answer: take the screenshot, tap the thumbnail that appears in the bottom-left corner before it disappears, and you are already in Markup. Everything below is about doing that well, and about the moment when Markup is the wrong tool and you should know it rather than discover it after sending.
The loop, in order
- Take the screenshot. Side button plus volume up on a Face ID phone, home plus side button on a Touch ID one. If you take a lot of them, Settings, Accessibility, Touch, Back Tap will let a double tap on the back of the phone do it.
- Tap the thumbnail in the bottom-left corner within a few seconds. That opens Markup directly on the fresh capture and, on recent iOS versions, offers a full-page option when the screenshot came from Safari.
- Cover first, before anything else. If you annotate first and cover second you will end up moving arrows around what you have covered. Covering is the part that must not be forgotten, so do it while it is the only thing on your mind.
- Point second. One arrow, or one rectangle, at the single thing you are talking about. Resist the second one until you have asked whether the first still reads.
- Crop last, using the handles on the edges of the image in the Photos editor. Cropping first throws away context you may want back, and there is no way to get it back once you have saved over the file.
- Save or share. Done gives you Save to Photos, Save to Files, and on recent versions Copy and Delete, which is the right answer when the screenshot itself was never meant to stay on your phone.
What the built-in Markup does well
The tool row along the bottom gives you a pen, a highlighter, a pencil, an eraser, a lasso for selecting things you have already drawn, and a ruler for straight lines. The plus button adds text, a signature, a magnifying loupe and four shapes: square, circle, speech bubble and arrow. Tapping a colour opens a picker with an opacity slider.
Two of those are better than they look. The lasso means the marks you make are objects, so a badly placed arrow is moved rather than undone and redrawn. And the magnifying loupe — a circular zoom you drag over part of the image and resize — solves a problem arrows cannot: showing a detail that is too small to read at the size the image will be viewed. On a dense settings screen a loupe over the one switch you mean is worth more than three arrows.
For a screenshot where nothing is sensitive and you need one arrow and one word of text, this is the whole job, it takes eleven seconds, and installing anything would be silly.
The two things it will not do
There is no mosaic and no blur
Markup has no pixelation and no blur of any kind. To hide a phone number you draw an opaque shape over it, which works but looks like exactly what it is: a rectangle of flat colour that says nothing about what is underneath. That is often fine — for anything that genuinely matters, a solid block is the correct choice anyway. It is less fine when you are covering nine names in a chat log and want the reader to still see that it is a chat log with nine people in it, which is precisely what a mosaic preserves and a black bar destroys.
What you must not do is reach for the highlighter or drop the opacity slider to make the cover look softer. A translucent cover is not a cover. Screenshots get brightened, and text under 40 percent black is legible with two seconds in any photo editor.
A cover you have not flattened can be taken off
While you are still in Markup, every shape you have drawn is an object. Tap it with the lasso and it moves. That is a feature during editing and a hazard afterwards, and it is the reason for the persistent advice never to hand someone a file you have not exported and looked at.
The larger version of the same problem is that Photos edits are non-destructive by design: the app keeps the unedited original so that Revert to Original can exist. Do not guess which path on which iOS version leaves that revert data behind — check. Open the finished image, tap Edit, and see whether Revert to Original is offered. If it is, the covered content is still on your phone, and anyone holding your unlocked phone can bring it back in two taps. Sharing normally sends rendered pixels rather than your edit history, but "normally" is not a standard you should apply to a bank card number.
Doing it in Marka
Marka is a screenshot markup app for iPhone, iPad and Mac, and the reason it exists is the gap above. Redaction is a brush: you drag your finger across the thing you want gone, rather than drawing a box and then hunting for a mode in a menu. Mosaic is free. Blur and a solid block are part of the one-time Pro purchase, alongside the nine annotation tools — arrow, rectangle, ellipse, line, pen, highlighter, text, numbered markers, stickers. Opening an image, cropping it with rotation and flip, brushing a mosaic, a hundred levels of undo and saving the result back to Photos cost nothing.
Two design decisions matter more than the tool list. Stroke weight and text size are proportions of the image’s short edge, not fixed pixel values, so an arrow on a 4K screenshot is not a hairline and one on a small crop does not swallow it. And nothing leaves the device: there is no server, no account, no analytics, and on iPhone and iPad the app asks for add-only photo access — permission to save the result, not to read your library. You pick the original through Apple’s own picker. It is a scratch pad rather than a library: it holds the image you are working on and keeps no copy once you close it, which is the correct behaviour for a tool that handles screenshots and worth knowing before you expect to find yesterday’s work in it.
Two habits worth having
- Look at the finished image at the size it will actually be seen. Open it in Photos and do not zoom. Most annotation that fails, fails because it was drawn at 300 percent zoom and read at 30 percent.
- Check the status bar, the notification banner and the top of the keyboard before you send. They are outside where you were looking, and they carry your carrier, the time, a preview of an unrelated message, and sometimes an autocomplete suggestion that says more about you than the screenshot does.
Frequently asked questions
Can I pixelate part of a screenshot with the built-in iPhone tools?
No. iOS Markup has a pen, a highlighter, a pencil, shapes, text, a signature and a magnifying loupe, but no pixelation and no blur. To hide something with the built-in tools you draw an opaque shape over it. That is a perfectly good redaction — arguably a better one than a mosaic — but if you want a mosaic look you need a different app.
Is a black rectangle drawn in Markup safe to send?
The pixels are, once the image is flattened into a file you exported and looked at. The risk is elsewhere: Photos keeps the unedited original so that Revert to Original can work. Open the finished image, tap Edit, and see whether Revert is offered. If it is, the original is still on your device, which matters when someone else holds your phone.
Should I crop before or after annotating?
After. Crop first and you throw away context you may want back, and if you saved over the file you cannot get it back. Annotate on the full image, decide what the image is about, then crop to it. The exception is a screenshot with something sensitive right at the edge, where a crop is the cheapest way to remove it entirely — cropping something out beats covering it.
How do I take a screenshot of a whole long web page?
In Safari, take a normal screenshot and tap the thumbnail; the markup screen offers a Full Page tab that captures the entire scrollable page. It saves as a PDF to Files rather than as an image to Photos, which is worth knowing before you go looking for it in your camera roll.
Is Marka in English?
No. The interface is Simplified Chinese in this version, with no localized strings in any other language. Every tool is an icon and the actual work happens on the canvas with your finger, so people do use it without reading Chinese, but if you need an English interface you should know that before you install rather than after.
What does the free version of Marka cover?
Opening an image, cropping it including quarter-turn rotation and horizontal or vertical flip, the mosaic redaction brush, a hundred levels of undo, and saving the result back to Photos or handing it to the share sheet. The nine annotation tools, the blur and solid redaction modes, the stickers and the backdrop are the one-time Pro purchase, at whatever price your own App Store shows.
Do it in Marka
Marka is a screenshot markup app for iPhone, iPad and Mac. Brush a mosaic over what should not be seen, point an arrow at what should, number the steps, crop it to the shape you are posting in, and send. Everything is processed on the device — no upload, no account, no analytics, and a 2.4 MB download. Opening, cropping, the mosaic brush and export are free; Pro is a one-time purchase that covers all three platforms.