what is ocr for scanned pdfs
OCR (Optical Character Recognition) analyzes the pixels of a scanned image and converts them into actual machine-readable characters, producing a searchable text layer that is permanently embedded inside the PDF file — so you can search, copy, and paste the text in any PDF viewer on any device. Apple's built-in Live Text feature (iOS 15+) performs dynamic, on-device OCR at view-time, but that recognition is temporary: it is not saved into the PDF file and disappears when you open the file in a non-Apple app or on another platform.
Réponse courte
OCR (Optical Character Recognition) analyzes the pixels of a scanned image and converts them into actual machine-readable characters, producing a searchable text layer that is permanently embedded inside the PDF file — so you can search, copy, and paste the text in any PDF viewer on any device. Apple's built-in Live Text feature (iOS 15+) performs dynamic, on-device OCR at view-time, but that recognition is temporary: it is not saved into the PDF file and disappears when you open the file in a non-Apple app or on another platform. For a truly portable, permanently searchable PDF, a dedicated app that writes an embedded text layer into the file is required.
ScanTo Pro fait tout cela sur votre iPhone : numérisation en PDF net, OCR exécutée sur l'appareil et verrouillage des fichiers par Face ID – une app à achat unique, sans abonnement. Consultez la fiche App Store pour les fonctionnalités actuelles.
À vérifier avant de choisir
- Embedded OCR text layer: saved into the file permanently, searchable on any device/OS
- Apple Live Text: on-device, private, real-time — but the text layer is NOT written into the PDF
- On-device OCR (e.g., Apple Vision / Core ML) keeps document images private; cloud OCR sends images to external servers
- OCR enables accessibility: screen readers and assistive technology can read the text aloud
- OCR accuracy depends on scan quality — sharp, high-contrast scans produce far fewer recognition errors
Un processus de décision pratique
- Embedded OCR text layer: saved into the file permanently, searchable on any device/OS.
- Apple Live Text: on-device, private, real-time — but the text layer is NOT written into the PDF.
- On-device OCR (e.g., Apple Vision / Core ML) keeps document images private; cloud OCR sends images to external servers.
- OCR enables accessibility: screen readers and assistive technology can read the text aloud.
- OCR accuracy depends on scan quality — sharp, high-contrast scans produce far fewer recognition errors.
Comparaison rapide
| Besoin | Ce qu’il faut vérifier | Pourquoi c’est important |
|---|---|---|
| Modèle tarifaire | Vérifiez si les fonctionnalités utiles exigent un abonnement, un déverrouillage par achat unique ou ni l’un ni l’autre. | L’app la moins chère le premier jour n’est pas forcément la moins chère après un an. |
| Modèle de confidentialité | Privilégiez le traitement sur l’appareil lorsque le contenu est sensible. | Les documents privés, CV, données d’étude et contenus familiaux méritent une gestion attentive. |
| Export / verrouillage propriétaire | Vérifiez les formats de fichiers, le partage, la sauvegarde et les options de suppression. | Une bonne app doit vous aider à terminer la tâche, pas enfermer votre travail. |
Quand ScanTo Pro est adapté
ScanTo Pro convient bien si vous voulez numériser de façon privée, sur l'appareil et sans abonnement.
Achat uniqueSans abonnementSur l’appareil
Ceci est un guide d'achat rédigé et publié par le développeur de l'app. Les fonctionnalités et les prix sur l'App Store pouvant évoluer, veuillez vérifier les détails sur la page du produit avant tout achat.
FAQ
Can I copy text from a scanned PDF on iPhone without an OCR app?
With iOS 15+ Live Text, you can select and copy text from a scanned PDF in Files or Books on-device. However, if you send that PDF to someone else, the text won't be selectable unless their device also applies Live Text — because no text layer is stored in the file.
What languages does on-device OCR support on iPhone?
Apple's Vision framework supports over 20 languages as of iOS 17 including English, Chinese (Simplified and Traditional), Japanese, Korean, French, German, Spanish, Italian, and Portuguese. Coverage continues to expand with each iOS release.
Is cloud OCR more accurate than on-device OCR?
Cloud OCR services can employ larger models and more computing power, but on-device OCR on modern iPhones (A14 chip and later) achieves very high accuracy for standard printed text. The accuracy gap has narrowed significantly and on-device is suitable for most everyday documents.