壓縮 JPG — 免費線上，無需上傳
Drop a JPG or JPEG photo into PicBrewery and download a smaller file re-encoded with MozJPEG — no account, no watermark, no upload. Everything runs in WebAssembly inside your browser.
See the JPEG section on the formats hub for codec details.
如何壓縮 JPG
- Open PicBrewery.
- Drag and drop your
.jpgor.jpegfile (or several) onto the drop zone. - PicBrewery decodes the JPEG and re-encodes JPEG, PNG, WebP and AVIF in parallel. Compare byte sizes in the results row — the JPEG column is your re-compressed JPG.
- Click the download icon on the JPEG cell, or use Download all as ZIP for batches.
PicBrewery 中的 JPG 壓縮原理
PicBrewery does not resize or crop images. Compression means re-encoding the same pixels with a modern JPEG encoder (MozJPEG) at tuned quality settings, EXIF, XMP, IPTC and C2PA are dropped; the color profile is kept.
For photos already saved at quality 85–90, a fresh MozJPEG pass at quality 75–80 often yields 10–30% smaller files with no visible difference. Gains are smaller if the source was already heavily optimized.
保留 JPG vs 轉為 WebP/AVIF
需要最大相容性（郵件、CMS、印刷）時保留 JPG。Web 交付請比較 WebP 與 AVIF 欄。JPG 轉 WebP或壓縮 WebP。
常見問題
壓縮 JPG 會降低畫質嗎？
Re-encoding JPEG is lossy — each save can add artifacts. PicBrewery defaults to quality settings tuned for size at matching perceived quality. Use the quality slider under Advanced settings if you need a higher bitrate.
JPG 會小多少？
Typical camera JPEGs shrink 10–30% after MozJPEG re-encode and metadata stripping. Drop your file into PicBrewery to see exact byte counts for every output format side by side.
EXIF 和 GPS 資料會保留嗎？
不會保留。重新編碼會去掉 EXIF、XMP、IPTC 和 C2PA Content Credentials，包括 AI 產生器留下的標記。色彩設定檔會保留。 移除 AI 標記和其他中繼資料.
可以批量壓縮 JPG 嗎？
Yes — up to 1000 files per batch, 20 MB each, with Download all as ZIP.
PicBrewery 會改變圖片尺寸嗎？
No. Compression here means re-encoding only — pixel dimensions stay the same.