Tap "Take a photo" to open the camera, or "From photo library" to import an existing image. After you capture or pick an image, Letterproof runs on-device OCR to find text regions, samples the colours of each region, and shows a contrast ratio and WCAG grade for every line. Tap any row to see the detail sheet including colour swatches, the contrast scale, a suggested fix, and colour-blindness simulations.
Support
Letterproof Support
Help and contact information for Letterproof v1.1.
Type a six-character hex code in each field (no # needed). The WCAG verdict and contrast ratio update instantly. Turn on "Large text" if the colours are used at 18 pt or larger — the AA threshold drops from 4.5:1 to 3:1. Tap "Swap colours" to reverse the pair. Tap "Colour-blindness simulations" to see how the pair looks under Deuteranomaly, Protanomaly, and Tritanomaly. Tap "Share report" to copy or send the result as plain text.
Email RobertCorbin84@gmail.com with your device model, iOS version, and a short description of what happened.
Common Questions
Does the app require an account or internet connection?
No. Everything — OCR, colour sampling, contrast math, and simulations — runs on your device. No account or network connection is needed or used.
Why did OCR miss some text?
Vision OCR works best on high-contrast text at a reasonable size. Very small text (under ~12 px in the image), text on busy backgrounds, or heavily stylised fonts may not be detected. For those cases, use the Manual tab and enter the hex codes directly.
What is a "large text" threshold?
WCAG 2.2 defines large text as 18 pt or larger (regular weight) or 14 pt or larger (bold). For large text, the AA minimum contrast is 3:1 instead of 4.5:1. Toggle "Large text" in the Manual tab, or Letterproof estimates the size from the bounding box height when auditing a photo.
What do the colour-blindness simulations show?
They show how the text and background colours appear to people with Deuteranomaly (~5% of males, reduced green sensitivity), Protanomaly (~1.3% of males, reduced red sensitivity), or Tritanomaly (rare, reduced blue/yellow sensitivity). The simulation uses the Machado, Oliveira, and Fernandes (2009) physiologically-based model. A pair that passes WCAG by ratio can still have low simulated contrast — this is especially common with red-on-green combinations.
What changed in v1.1?
Three new features: the Manual tab (type any two hex codes for an instant WCAG result), colour-blindness simulations in every reading detail sheet and the Manual tab, and a share/export button that generates a plain-text audit report.
Where is my audit history stored?
Audits are saved locally as a JSON file in the app's Documents folder on your device. No data leaves the device through the app. You can delete all audits from the History tab menu or Settings.
What is WCAG?
The Web Content Accessibility Guidelines (WCAG), published by the W3C, define contrast requirements so that text is readable by people with low vision or colour-vision deficiencies. WCAG 2.2 is the current standard and underpins accessibility laws in many countries. Letterproof checks contrast ratios against the AA and AAA levels of Success Criterion 1.4.3.