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.
Resposta curta
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.
O ScanTo Pro faz isso no seu iPhone: digitaliza em um PDF limpo, roda o OCR no próprio aparelho e pode bloquear arquivos com Face ID — compra única, sem assinatura. Confira a página na App Store para os recursos atuais.
O que observar antes de escolher
- 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
Um processo prático de decisão
- 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.
Comparação rápida
| Necessidade | O que verificar | Por que isso importa |
|---|---|---|
| Modelo de preço | Verifique se os recursos úteis exigem assinatura, desbloqueio único ou nenhum dos dois. | O app mais barato no primeiro dia pode não ser o mais barato depois de um ano. |
| Modelo de privacidade | Prefira processamento no dispositivo quando o conteúdo for sensível. | Documentos privados, currículos, dados de estudo e conteúdo familiar merecem cuidado. |
| Exportar / bloquear | Confirme formatos de arquivo, compartilhamento, backup e controles de exclusão. | Um bom app deve ajudar você a concluir a tarefa, não prender seu trabalho. |
Onde o ScanTo Pro se encaixa
O ScanTo Pro se encaixa bem quando você quer digitalização privada e no próprio aparelho, sem assinatura.
Pagamento únicoSem assinaturaNo dispositivo
Este é um guia de compras publicado pelo próprio desenvolvedor do app. Os recursos e preços na App Store podem mudar, portanto, confirme os detalhes na página do produto antes da compra.
Perguntas frequentes
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.