電子郵件伺服器會拒絕超過 25MB 的附件，而且大照片會讓收件者感到困擾。傳送前先壓縮你的圖片，這樣它們就能快速送達，並可輕鬆放進收件匣。
這個工具在你的瀏覽器中本地壓縮圖片 — 不會上傳任何內容。
如何使用此工具
新增你的圖片
將你的照片拖曳到工具上，或從你的檔案中選擇它。
目標品質
已預先選取 JPG。70–80 的品質能讓照片看起來很棒，同時大幅縮小檔案大小。
檢查最終大小
每張照片的目標是低於 1MB — 對電子郵件來說綽綽有餘，也遠低於供應商的限制。
下載並附加
下載你壓縮後的圖片，然後將它附加到電子郵件中。
本節目前僅提供英文版本。
What email actually needs
Email is the most size-constrained place an image goes. Most providers cap attachments at 20–25 MB, and many corporate mail systems are stricter — some reject anything over 10 MB, and a few over 5 MB. Base64 encoding used by mail transfer adds roughly 33% on top of the file size, so a 20 MB image becomes about 27 MB on the wire.
The practical target is a few hundred kilobytes per image, which keeps a message with several attachments comfortably small and courteous to the recipient’s inbox.
Sensible targets
| What you are sending | Target size | Notes |
|---|---|---|
| A photo to a friend or colleague | 200–500 KB | Plenty for screen viewing |
| Several photos in one message | Under 2 MB total | Compress each, or use a link |
| A document scan or receipt | Under 500 KB | Keep text legible; do not over-compress |
| A screenshot for a bug report | Under 300 KB | PNG or lossless WebP; text stays sharp |
| A print-quality image someone will print | Do not email it | Send a link or a transfer service instead |
Resize first, compress second
A modern phone photo is often 4000 pixels wide and 4 MB. Nobody needs that in an email. Resizing to 1600 pixels on the long edge — which still fills a laptop screen — cuts the data by roughly 85% before any compression setting is touched. Doing the resize first means the compressor has far less work to do and the result looks better.
Keeping scans readable
Compressing a scan of a document is the one case where over-compression really bites: JPEG artefacts land on the letter edges and small print becomes smeared. Use PNG or lossless WebP for anything text-heavy, and if it is still too large, reduce the resolution to around 150 DPI rather than crushing the quality.
常見問題
圖片用於電子郵件的理想大小是多少？
每張圖片低於 1MB 最理想。大多數供應商將附件上限設為總共 25MB，因此檔案越小，你能傳送的照片就越多。
電子郵件最適合用 JPG 嗎？
JPG 是電子郵件中照片相容性最高的格式。有些電子郵件用戶端會移除或封鎖其他格式。
這會上傳我的照片嗎？
不會 — 壓縮完全在你的瀏覽器中進行。