Compress Image
Reduce JPG, PNG, or WebP file size locally
Compress Image — what it does
Reduce the file size of a single JPG, PNG or WebP by re-encoding it at a quality level you set, entirely inside the browser. The pixel dimensions stay the same; what changes is how much data is spent describing them, which on a typical photo is where most of the megabytes are hiding.
When this tool helps
- Getting a photo under an upload size limit on a form or listing site.
- Cutting page weight before publishing an image to a website.
- Trimming an email attachment that a mail server would otherwise reject.
How to use it
- Choose the image file.
- Set the quality level.
- Process the compression.
- Compare the resulting size and download the file.
Accuracy, limits, and good practice
- Quality between 0.7 and 0.8 usually removes half the file size with no difference visible at normal viewing size.
- Screenshots with text degrade faster than photographs; keep them higher quality or use PNG to preserve sharp edges.
- Compression is lossy and permanent, so always keep the original — you cannot re-derive detail from a compressed copy.
- Compare the two files at full size before accepting the result; a saving that looks free at thumbnail size can be visible where it matters.
Frequently asked questions
Does it change the image dimensions?
No. Use the resizer if you need fewer pixels; compression only changes encoding quality.
Why did my PNG barely shrink?
PNG is lossless, so quality settings have limited effect. Convert photos to JPG or WebP for meaningful savings.
Can I compress a batch of images?
Yes, the batch image compressor applies one setting across many files and returns them as a ZIP.
Does the tool strip metadata as well?
Re-encoding drops EXIF, which shrinks the file a little further and removes camera and location tags along the way.
Related tools on this site
- JSON Formatter — Format and validate JSON
- Add Image Stamp to PDF — Apply a logo or stamp image to every PDF page
- Reset PDF Page Rotation — Set page rotation metadata back to zero degrees
Everything above runs inside this page. Compress Image needs no account, no upload, and no server round trip — close the tab and nothing is left behind.
壓縮圖片能做什麼
在瀏覽器內以你設定的品質重新編碼單張 JPG、PNG 或 WebP，降低檔案大小。像素尺寸不變，改變的是用多少資料來描述它們——在一般照片上，肥大的 MB 數多半就藏在這裡。
什麼時候用得上
- 讓照片符合表單或刊登網站的上傳容量限制。
- 在圖片發佈到網站前先減少頁面重量。
- 縮減會被郵件伺服器退回的信件附件。
使用步驟
- 選擇圖片檔案。
- 設定品質等級。
- 執行壓縮。
- 比較結果大小並下載檔案。
精確度、限制與實務建議
- 品質 0.7 至 0.8 通常能砍掉一半檔案大小，在正常觀看尺寸下看不出差異。
- 含文字的截圖比照片更快劣化，請維持較高品質或改用 PNG 以保住銳利邊緣。
- 壓縮是有損且不可逆的，原檔請務必保留——壓過的副本無法還原細節。
- 接受結果前請以完整尺寸比較兩個檔案；在縮圖上看起來白賺的壓縮量，放大後可能就看得出代價。
常見問題
會改變圖片尺寸嗎？
不會。需要更少像素請用縮放工具；壓縮只改變編碼品質。
為什麼我的 PNG 幾乎沒變小？
PNG 是無損格式，品質設定作用有限。照片改存 JPG 或 WebP 才會明顯變小。
可以整批壓縮嗎？
可以，批量圖片壓縮工具會用同一組設定處理多個檔案並打包成 ZIP。
會順便清掉中繼資料嗎？
重新編碼會丟棄 EXIF，檔案再小一些，相機與定位標籤也一併移除。
本站相關工具
- JSON 格式化 — 格式化並驗證 JSON
- PDF 加入圖片印章 — 在每一頁 PDF 加入 Logo 或印章圖片
- 重設 PDF 頁面旋轉 — 將頁面的旋轉中繼資料重設為零度
以上步驟全部在這個頁面內完成，壓縮圖片 不需要註冊、不上傳檔案、也不經過伺服器，關閉分頁後不會留下任何資料。