In 2018, 9to5Mac showed a Markup stroke over text, opened Photos Edit, dragged brightness and brilliance, and the words came back. Lifehacker followed with a blunt headline: stop using the highlighter to hide personal info. The control is still in Markup. It still looks like a marker. People still send those files to landlords, teachers, and group chats.
The failure is not that Apple hid a secret “unredact” button. The failure is that a highlighter is a tint. Tints keep contrast. Contrast can be stretched. This page is that tint demo and the audit that catches it before you hit Send. It is not a full iPhone capture guide (iPhone steps) and not the PETS mosaic paper (PETS 2016).
What the brightness slider is actually stretching
Highlighter in Markup is often a translucent overlay. The glyphs under it are still in the samples, just washed. Brightness and brilliance stretch the remaining contrast until those glyphs are readable again. A filled rectangle, or pixels replaced in a PNG, does not leave leftover contrast to stretch. That is the whole distinction.
If you can still see a ghost of the letter in Markup before you export, a recipient can often see more after they open Edit. You do not need a special app to try this on a file you already “covered.” Photos is enough. That is why the 2018 write-up mattered: the reveal used the same phone that made the screenshot.
Open larger image in a new tabHow to cover text in Markup with a filled shape
A solid fill that fully covers the glyphs, saved as a new image, is the Markup path that matches deletion. Pen tool at full opacity can work. A filled square is easier to audit. Duplicate the screenshot first so you still have the original for yourself.
- Open the screenshot in Photos. Tap Edit, then the Markup pencil, or tap Markup from the share sheet.
- Skip the highlighter. Tap the + control and pick a square or rectangle. Set fill to a solid color. Black is honest.
- Drag the shape until no glyph peeks, including descenders and the gap between digit groups. Pinch to zoom. What you should see is a hard slab, not a yellow wash.
- Tap Done, then save a copy. Send that copy. Do not tap Share Original.
- Open the copy, tap Edit, and drag brightness and brilliance yourself. If words return, you still used a tint. Paint again.
iPad has the same trap with a larger canvas: iPad screenshots. The device guides own capture keys. This page owns the highlighter failure mode.
How to bake a PNG instead of trusting Markup
Markup is fine offline for an arrow on a bug. It is a weak privacy product. If the region is a secret you would rotate, skip the marker and replace pixels in a browser tab that never uploads.
- Open BlurThis in Safari. Pick the screenshot from Photos.
- Drag a Black bar over the run. Pad past the edges. Zoom with two fingers.
- Download
redacted.png. Files app will show it. Share that PNG. - Do not take a second screenshot of Safari to “save” it. That reintroduces compression and maybe the Safari chrome.
Open larger image in a new tabWhat you should see on the baked PNG: an opaque rectangle. Open it, raise brightness, and the interior should stay empty.
Is blur in Markup safer than highlighter?
Markup does not give you a Gaussian you should trust for OTPs, cards, or recovery codes. Short strings plus leftover structure is the case document-redaction research already flagged for mosaic and blur. A highlighter is worse because it is often not even a blur. If the region is a secret you would rotate, opaque fill or a canvas bar.
Faces in a group photo are a different bar: “not identifiable at a glance.” Passwords are not faces. Do not reuse the glance standard.
Who still receives highlighter “redactions”?
Landlords reviewing rent statements. HR reviewing ID photos. Teachers reviewing homework stills. Group chats that forward “just the address.” The 2018 demonstration did not retire the tool. It is still the first Markup control that feels like covering. Recipients who never read 9to5Mac can still open Edit. Recipients who did read it can still open Edit. Do not make that the control that stands between a statement and a bank number.
If you already sent a highlighter file, assume the text is readable. Rotate what you can. Send a filled export next, not a brighter copy of the same layer.
Does saving or sharing flatten the highlighter?
Flattening can bake a translucent stroke into pixels and still leave contrast. Baked tint is still tint. The 9to5Mac steps were brightness and brilliance on the image, not “open the Markup layer list.” If the glyphs are in the samples, sliders can stretch them. Lifehacker’s advice stands after a share sheet: stop using the highlighter as a hide tool.
AirDrop, Mail, and Messages are not a redaction step. They transport whatever you saved. Save a filled copy with a new name. Open that copy. Try the sliders. Send that copy. Leave the highlighter original in Recents if you must, but do not attach it. If the recipient opens Photos Edit, they are repeating the 2018 demonstration, not hacking your phone.
If brightness still lifts the text
You used a tint, a pen at reduced opacity, or a shape that did not cover the descenders. Switch to a filled rectangle at 100%. Or skip Markup and download a canvas PNG. Check the top of the frame too: a banner that landed while you held the buttons is a second leak. Banners in the shot.
Chat apps may recompress the PNG into a JPEG cousin. Start from a real fill anyway. Ringing around a highlighter smear is how glyphs get an outline. PNG note.
What to do instead of the marker
Duplicate first. Filled shape in Markup, or skip Markup. Paint a rectangle, download PNG, inspect the download on the phone: zoom, then try brightness. If words return, you still used a tint. Paint again. Send the copy that survived your own sliders. Skip the marker and replace the pixels in the tab: use a canvas bar in BlurThis.
