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圖片壓縮

選擇壓縮等級

點擊或拖拽添加圖片

支援 PNG、JPG、JPEG、WEBP、GIF、AVIF、BMP、ICO、HEIC、JXL、TIFF，單張須小於 20MB，單次最多 10 張

免費線上圖片壓縮工具，支援 JPG/PNG/WEBP/GIF/AVIF/HEIC 等11種格式，極度/推薦/輕度三種壓縮等級，批量壓縮即時顯示壓縮率。檔案2小時後自動刪除。

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適用場景

  • Web optimization: reduce image payload for faster load times and better SEO (Core Web Vitals)
  • Email attachments: compress to fit email size limits (typically 10-25MB)
  • Form uploads: compress images for applications, resumes, and form submissions with size limits
  • Social media: WeChat, Xiaohongshu, Weibo etc. have image size limits
  • E-commerce: batch compress product images to speed up store pages
  • Format compatibility: convert/compress Apple HEIC photos to universal JPG/WEBP

功能特點

  • 11 formats supported: JPG/JPEG/PNG/WEBP/GIF/AVIF/BMP/ICO/HEIC/JXL/TIFF including Apple HEIC and AVIF
  • Three levels: Extreme (q=20), Recommended (q=75), Light (q=90) for different needs
  • Batch compression: queue multiple images, each with independent size/ratio display
  • Real-time ratio: shows before/after size and compression percentage per image
  • Job history: automatically records recent compression jobs for easy re-download
  • Privacy: files upload to server for processing, auto-deleted after 2 hours

使用方法

  1. Click upload area or drag-drop images; batch supported (max 20MB/file)
  2. Select compression level: Recommended, Extreme, or Light
  3. Wait for compression; view before/after size and ratio per image
  4. Download compressed images individually; re-compress with different level if needed

常見問題

Will compression make images blurry?

Depends on level. Recommended (quality 75) is nearly indistinguishable to the naked eye for web/email/social use while reducing size by 40-70%. Use Light (quality 90) for maximum quality retention.

What formats are supported?

11 formats: JPG/JPEG, PNG, WEBP, GIF, AVIF, BMP, ICO, HEIC, JXL, TIFF — including Apple HEIC photos and next-gen AVIF. Max 20MB per file.

Can I compress multiple images at once?

Yes, batch-add multiple images to queue. Each compresses independently with its own ratio displayed. Ideal for e-commerce product images, blog assets, and social media content.

Are uploaded images stored?

Images upload via encrypted channel to the compression server. Files are automatically deleted 2 hours after processing and are not retained or used for any other purpose. Download promptly after completion.

JPG vs PNG vs WEBP — which compresses best?

If output format is flexible, WEBP and AVIF offer the best compression — 25-35% smaller than JPG at equivalent quality. If keeping the original format, Recommended mode works best on JPG.

Why did the file size increase after compression?

Rarely, re-compressing an already highly compressed image can slightly increase size. If the source is already a low-quality JPG (quality < 50), use Light mode. Negative ratio means no gain — you can download the original instead.

Does compression change image resolution?

No. Compression only reduces data size (quality parameter), not pixel dimensions (width/height). To also reduce dimensions, use the Image Resize tool.

Image Resize

什麼是圖片壓縮？

圖片壓縮透過演算法減少圖片檔案體積，分為有損壓縮（JPG/WEBP）和無損壓縮（PNG）。有損壓縮丟棄人眼不敏感的資料大幅減小體積；無損壓縮僅優化編碼。

未優化的圖片往往佔頁面流量 50% 以上，直接影響 Core Web Vitals 的 LCP 指標和 SEO 排名。

推薦壓縮（quality 75）是絕大多數場景的最佳平衡點，體積減少 40-70%，視覺幾乎無差別。

若平台支援優先使用 WEBP/AVIF 格式，同等畫質下比 JPG 小 25-50%。

本工具支援 11 種格式，單檔最大 20MB，檔案上傳後 2 小時自動刪除。

术语表

Lossy Compression
Reduces file size by discarding data (primarily high-frequency chroma information). JPG, WEBP (default), AVIF are lossy. High compression ratio but some quality loss; lower quality = more loss.
Lossless Compression
Reduces size via encoding optimization without losing any pixel data. PNG, GIF, WEBP (lossless mode). Lower ratio but perfectly reconstructs original.
Quality Parameter
Core parameter in lossy compression, typically 0-100. Higher = better quality but larger file. 75 is the sweet spot (Google PageSpeed recommended).
WEBP
Google image format (2010) supporting lossy/lossless, transparency, and animation. 25-35% smaller than JPG at equivalent quality — recommended for modern web.Wikipedia - WebP
AVIF
Next-gen format based on AV1 video coding (2019), ~20% smaller than WEBP. Supports HDR, wide gamut, transparency, animation. Chrome 85+/Firefox 93+ support it natively.Wikipedia - AVIF
HEIC/HEIF
High Efficiency Image File Format, Apple iOS 11+ default photo format, better compression than JPG. Limited compatibility on Windows/Android, often converted to JPG.
Core Web Vitals
Google's web UX metrics; LCP (Largest Contentful Paint) is directly affected by image loading speed. Image compression/format optimization is the most effective LCP improvement.
LCP
Largest Contentful Paint — measures when the main page content finishes loading. Google recommends LCP < 2.5 seconds. Compressing hero images and using WEBP/AVIF are key optimizations.
Metadata
Extra information in image files beyond pixel data: EXIF (camera model, GPS, timestamp), ICC Profile, etc. Stripping metadata saves KB to tens of KB and protects location privacy.
DPI/PPI
Dots/Pixels Per Inch — a print resolution unit meaningless for screen display. Screens care about pixel dimensions (W×H); compression does not change DPI or pixel dimensions.

Three Compression Levels Comparison

LevelQualityTypical SavingsVisual QualityBest For
Extreme2070-90%Lower, may show artifactsAvatars, thumbnails, size-critical scenarios
Recommended7540-70%High, virtually indistinguishableWeb images, email attachments, social media (recommended)
Light9010-30%Highest, visually losslessProduct photos, photography requiring max quality

Image Format Comparison

FormatCompressionBest UseTransparencyAnimation
JPG/JPEGLossyPhotos, realistic images❌❌
PNGLosslessIcons, screenshots, text images, transparency needed✅❌
WEBPLossy/LosslessWeb images (25-35% smaller than JPG/PNG)✅✅
AVIFLossy/LosslessNext-gen format (smaller than WEBP)✅✅
GIFLossless (256 colors)Simple animations✅ (1-bit)✅
HEIC/HEIFLossyApple device photos✅❌

Authoritative References