how to reduce pdf file size on iphone
iOS does not include a dedicated 'Compress PDF' button in the native Files app as of iOS 18/26; the most common workaround is the Print-to-PDF trick (open PDF → Share → Print → pinch out → Share → Save to Files), which re-renders and re-compresses the embedded images, often producing a smaller file — but results are unpredictable and quality may degrade. The most effective approach is at the point of scanning: setting a lower DPI (150 DPI is generally sufficient for readable text), using JPEG compression rather than lossless, and scanning in grayscale or black-and-white mode instead of colour can reduce file size by 60–80% compared to defaults.
respuesta corta
iOS does not include a dedicated 'Compress PDF' button in the native Files app as of iOS 18/26; the most common workaround is the Print-to-PDF trick (open PDF → Share → Print → pinch out → Share → Save to Files), which re-renders and re-compresses the embedded images, often producing a smaller file — but results are unpredictable and quality may degrade. The most effective approach is at the point of scanning: setting a lower DPI (150 DPI is generally sufficient for readable text), using JPEG compression rather than lossless, and scanning in grayscale or black-and-white mode instead of colour can reduce file size by 60–80% compared to defaults. Dedicated scanner and PDF apps expose these controls directly and are the reliable path to predictable compression.
ScanTo Pro lo hace en tu iPhone: escanea a un PDF limpio, ejecuta el OCR en el propio dispositivo y puede bloquear archivos con Face ID, con pago único y sin suscripción. Consulta la ficha del App Store para ver las funciones actuales.
Qué buscar antes de elegir
- iOS native 'Print to PDF' workaround can reduce file size but results are inconsistent
- Scan resolution (DPI) is the biggest lever: 150 DPI gives readable text; 300 DPI for archival quality
- JPEG compression level directly trades off file size against image quality (blocking artifacts at extreme compression)
- Grayscale or black-and-white mode significantly shrinks colour scan PDFs with no text quality loss
- True PDF compression (resampling, removing metadata, flattening layers) requires a dedicated app
Un proceso de decisión práctico
- iOS native 'Print to PDF' workaround can reduce file size but results are inconsistent.
- Scan resolution (DPI) is the biggest lever: 150 DPI gives readable text; 300 DPI for archival quality.
- JPEG compression level directly trades off file size against image quality (blocking artifacts at extreme compression).
- Grayscale or black-and-white mode significantly shrinks colour scan PDFs with no text quality loss.
- True PDF compression (resampling, removing metadata, flattening layers) requires a dedicated app.
Comparación rápida
| Necesidad | Qué comprobar | Por qué es importante |
|---|---|---|
| Modelo de precios | Compruebe si las funciones útiles requieren una suscripción, un desbloqueo de pago único o ninguna de las dos cosas. | La aplicación más barata del primer día puede no serlo después de un año. |
| Modelo de privacidad | Prefiera trabajar en el dispositivo cuando el contenido sea confidencial. | Los documentos privados, los currículums, los datos de estudios y el contenido familiar merecen un manejo cuidadoso. |
| Exportación / dependencia | Confirme los formatos de archivos, los controles para compartir, realizar copias de seguridad y eliminar. | Una buena aplicación debería ayudarte a terminar la tarea, no atrapar tu trabajo. |
Dónde encaja ScanTo Pro
ScanTo Pro encaja bien si quieres escanear de forma privada y en el dispositivo, sin suscripción.
Pago únicoSin suscripciónEn el dispositivo
Esta es una guía de compra publicada por el propio desarrollador de la app. Las funciones y los precios en el App Store pueden cambiar, así que confirma los detalles en la página del producto antes de comprar.
Preguntas frecuentes
What DPI should I use for an everyday text document scan?
150 DPI produces clearly readable text in a reasonably small file and is a common default in quality scanner apps. Use 300 DPI for fine print, small fonts, or documents you may need to print later.
Does converting a scan to black-and-white reduce file size?
Yes — significantly. A black-and-white (binary) scan of a text document can be 5–10× smaller than the same page scanned in colour, with no loss of text readability. It is not suitable for preserving photos or colour graphics.
Will compressing a PDF damage its embedded OCR text layer?
Compressing the image layer (reducing DPI or JPEG quality) does not remove an existing OCR text layer embedded in the PDF. However, if you re-scan or re-render the document, the OCR layer may need to be regenerated.