Preview is the default image and PDF viewer on macOS, and many users assume it can handle OCR — recognizing and extracting text from images and scanned documents. In limited situations it can, thanks to Live Text integration. But for many common scenarios, Preview either silently fails to recognize text or provides no extraction capability at all. If you've tried to select text from a scanned PDF or a photo of a document in Preview and your cursor just draws a selection rectangle with no text highlight, you've hit Preview's OCR wall.
Where Preview's Text Recognition Breaks Down
Scanned PDFs with complex layouts. Preview can sometimes recognize text in clean, well-scanned single-column documents. But multi-column layouts, tables, headers and footers, and documents with mixed graphics and text often produce no selectable text at all. The Live Text engine in Preview doesn't handle complex document structures reliably.
Low-contrast or small text. Receipt scans, faded documents, and images with low contrast between text and background frequently defeat Preview's recognition. The text might be perfectly readable to human eyes but invisible to Preview's detection.
Handwritten text. Preview's text recognition is tuned for printed fonts. Handwritten notes, whiteboard photos, and annotated documents are rarely recognized, even when the handwriting is clean and legible.
Non-Latin scripts. Support for non-Latin languages is inconsistent. CJK, Arabic, and Cyrillic text in images may or may not be detected depending on font style, image quality, and document complexity.
No capture from screen. Preview only processes files you've opened. If the text you need is in a video frame, a web app interface, an error dialog, or another app's window, Preview has no way to reach it.
OCR That Works Across Everything on Screen
Optic bypasses Preview's limitations entirely by working at the screen level. Instead of asking a file viewer to recognize text inside a file, Optic reads characters from whatever is visible on your display. Open the problematic document in Preview — or any other app — and drag Optic's selection over the text you need.
Complex Document Layouts
Tables, multi-column text, and mixed content that stumps Preview are readable by Optic because you control exactly which region to scan. Select just the column or table cell you need — no full-page parsing required.
Beyond Files
Optic isn't limited to opened files. Video frames, dialogs, web apps, remote desktop sessions — anything rendered on screen is fair game. Preview can never reach these sources; Optic reads them as naturally as any image.
Persistent History
Preview has no memory of past text recognition attempts. Optic saves every extraction in the menu bar, building a log of captured text you can scroll through and re-copy at any time.