跳到主要内容
PPDF123

Shrink a PDF to Fit an Email

Compress PDF for Email reduces a PDF toward a 10 MB target so it fits common attachment limits, leaving images untouched when the file already fits. It shows the size before and after and whether the target was met.

把文件拖到这里，或点击选择

支持 PDF · 单个文件不超过 500.0 MB · 一次最多 20 个文件

也可以按 Ctrl/Cmd+V 或从剪贴板菜单粘贴文件。

Mail providers cap attachment size, often at around 20 to 25 MB, and attachments are base64-encoded for transport, which makes them roughly a third larger than the file on disk. A 10 MB PDF therefore travels as about 13 MB, comfortably inside most limits. This page presets the target to 10 MB; lower it for stricter systems.

If your PDF is already under the target, the tool only repacks its internal streams and leaves every image as it is. Only a file above the target is pushed through JPEG re-encoding, from mild settings to stronger ones, and the process stops as soon as the file fits.

Text, fonts and vector art are never changed, so contracts and reports stay crisp. Large embedded photos and scans are where the savings come from. If the file still cannot get under the target, you get the smallest result with a message saying so.

功能

  • 10 MB preset that leaves room for email encoding overhead
  • Does not touch images in a file that already fits the target
  • Before and after sizes plus a target met or missed message
  • JPEG quality and image size cap are reported
  • No account, no watermark

适用场景

  • Sending a scanned contract or invoice bundle that bounced for size
  • Emailing a slide-deck PDF full of photos to a client
  • Getting under a company mail gateway limit before sending

How do I compress a PDF for email?

  1. Upload the PDF you want to email
  2. Keep the 10 MB target, or lower it to match your provider's limit
  3. Click Process
  4. Download the smaller file and attach it to your message

限制与边界

  • Provider limits vary and change; check yours and lower the target if needed
  • The target is best effort; very image-heavy files may remain larger
  • Only JPEG and 8-bit RGB or gray images are re-encoded

测试结果与条件

  • Test file: a one-page PDF holding one 1400 × 1400 px noise-textured photo-like image, 5.1 MB. It is synthetic, so real photos will land differently. With the 10 MB target the file already fit, so it was only repacked: 5.1 MB became 4.7 MB and the image was left untouched (no JPEG re-encoding).

本工具的隐私说明

Files are uploaded over HTTPS, processed in memory or a short-lived temporary directory on our servers, and deleted when your result is ready. We do not keep copies for later browsing, training, or advertising profiles. See the Privacy Policy for retention details and AdSense cookie disclosures.

常见问题

What size should an emailed PDF be?
Staying near 10 MB or below is safe for most providers, because the attachment grows by about a third when encoded. Check your provider's stated limit and subtract that overhead.
Will compression change how my document looks?
If the file already fits the target, images are left alone. Otherwise images are re-encoded as JPEG, mildly first, so text stays sharp and photos may soften.
What if the PDF is still too big for email?
Use a smaller target such as 5 MB, split the PDF into parts, or send a download link instead of an attachment.
Does the tool email the file for me?
No. It only produces the smaller PDF for you to download and attach yourself.

最后更新:

用代码调用

本站每个工具都是普通 REST 接口。匿名使用不需要账号或 API Key，给浏览器、开发者和智能体同样可用。

curl -X POST "https://pdf123.xyz/api/v1/misc/compress-pdf" \
  -F "[email protected]" \
  -o output.pdf

也提供 MCP 工具，供说 Model Context Protocol 的客户端调用（JSON-RPC 2.0，POST /mcp）。 完整 API 文档

在 AI 代理中使用

Skill

装上这个 Skill，Claude Code、Codex、Cursor 等 AI 代理就能替你完成「压缩 PDF」： /skills/pdf123-compress.md

全部 Agent Skill

文件只用于本次处理，完成后自动删除。