iPhone highlighter doesn’t hide text. Photos can undo it.

9to5Mac did not bury this in 2018. They showed a Markup stroke over text, then Photos → Edit → brightness / brilliance, and the words returned. Lifehacker followed with a blunt headline: stop using the highlighter to hide personal info.

The control is still there. 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.

What is the slider actually doing?

Highlighter in Markup is often a translucent overlay. Brightness stretches the remaining contrast until glyphs are readable again. A filled rectangle, or pixels replaced in a PNG, does not have 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.

Does a filled shape in Markup fix it?

A solid fill that fully covers the glyphs, saved as a new image, is the Markup path that matches deletion. Pen tool, opaque color, fat coverage, no peeking stems. Shapes → filled square is easier to audit than freehand highlighter. Zoom in. If a descender peeks, the shape is too small.

iPhone walkthrough: iPhone steps. iPad is the same Markup trap with a larger canvas: same trap.

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, HR, teachers, group chats, support inboxes. 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 rent 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.

What should you do today instead of the marker?

Filled shape in Markup, or skip Markup. Paste the screenshot into a browser editor, paint a rectangle, download PNG. Inspect the download on the phone: zoom, then try brightness yourself. If words return, you still used a tint. Paint again.

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.

Skip the marker and replace the pixels in the tab. Try brightness on your own export before anyone else does: use a canvas bar in BlurThis.