Guia completo: reduzir PDF escaneado

Por que scans são grandes

Scanners save each page as a large image. A 300–600 DPI scan can be several megabytes per page, so long documents quickly reach 50–200 MB. Unlike text‑based PDFs, scanned files don’t compress well with simple metadata cleanup.

The good news: scanned PDFs have significant redundancy. Image recompression, careful quality settings, and avoiding unnecessary color data can reduce size dramatically without making text unreadable.

PDFThin focuses on the content that matters: text clarity and page order. You choose the target, and the tool balances size vs readability.

Preserve a legibilidade

Smart quality automatically searches for the highest acceptable quality that still fits your target size. This is ideal for receipts, IDs, contracts, and reports where small text must remain legible.

If you use a strict size limit (like 20 MB for Outlook), Smart quality will step down the image quality only as much as needed. The result is a smaller file with the best possible clarity for that target.

When scans are very noisy or high‑contrast, a slightly lower target size often yields better results than a maximum‑quality preset.

Defina um alvo

Comece com um preset de email se você pretende enviar o arquivo como anexo. O Gmail usa 25 MB, o Outlook costuma usar 20 MB e o Outlook.com suporta 25 MB. Se o seu PDF estiver um pouco acima do limite, defina uma meta personalizada 2–5 MB menor para evitar a sobrecarga de codificação.

If your document is for storage or upload, choose a practical target that keeps pages readable (often 150–250 KB per page for grayscale scans). For 200 pages, a 30–50 MB target is usually a good starting point.

PDFThin will try to keep page dimensions the same and avoid destructive operations. If a file still cannot fit, use split by size for a guaranteed result.

Practical checklist for scanned PDFs

1) Use Smart quality. 2) Pick an MB target aligned with your delivery channel. 3) If the file is still too large, split into parts. 4) Always preview a few pages to confirm readability.

If you’re scanning in color but only need black‑and‑white output, consider rescanning in grayscale to reduce size at the source. For already‑scanned files, Smart quality offers the most reliable balance.

Start here: Email‑ready compression or Split by size.

Por que scans são tão grandes?

Porque cada página é uma imagem.

O texto continuará legível?

Sim, comece com qualidade inteligente ou equilibrada.

E se ainda não couber?

Divida em partes abaixo do limite.

Outras ferramentas

Com limites, divida: Dividir por tamanho.

Todas as ferramentas PDF

Todas as ferramentas PDFThin num só lugar.

Compressão para e-mail

Reduza PDFs aos limites Gmail/Outlook com controlo de qualidade.

Dividir por tamanho

Divida PDFs grandes em partes seguras.

Organizar PDF

Unir, rodar, eliminar, reordenar e dividir páginas.

Todos os guias de PDF

Explore todos os guias passo a passo.

Guia completo: comprimir PDF para email

Workflow passo a passo para limites do Gmail 25MB e Outlook 20MB.

Reduzir o tamanho de PDF digitalizado

Mantenha o texto legível enquanto reduz digitalizações.

Dividir PDF por tamanho

Crie partes abaixo de um limite em MB.

Rodar páginas PDF online

Corrija a orientação de digitalizações ou fotos de lado.