压缩 图片
在保持最佳质量的同时减小JPEG、PNG和WebP图片的大小。
将图片拖放到此处
或 点击选择
JPEG, PNG, WebP, GIF — 最大50 MB
质量
75%
Publicité
实际效果
典型文件的实际压缩示例
前 / 后
之前
之后
75%
平均压缩率
5s
平均时间
按模式压缩比
"我的3MB照片压缩到不到300KB，几乎看不出差别，太棒了！"
How to compress an image online without quality loss?
Image compression reduces file size by 50 to 80% while preserving visual quality. FileSwiftly optimises your JPEG, PNG, WebP and GIF files directly in your browser with no installation required. The result: lighter images that load faster on the web.
JPEG, PNG and WebP compression: how it works
For JPEG photos, a quality setting of 75–85% is the standard used by Google, Facebook and Instagram — visually indistinguishable from the original but 60–75% lighter. Our algorithm analyses each image zone and applies stronger compression to uniform areas (sky, backgrounds) and lighter compression to detail zones (faces, textures). For PNG images (logos, screenshots, illustrations with transparency), lossless compression reduces size by 20–40% without changing a single pixel. The WebP format, developed by Google, achieves up to 30% additional compression over JPEG at equivalent quality — natively supported by all modern browsers.
Why optimise your website images?
Images account for an average of 60% of a web page's total weight. Unoptimised images slow load times, hurt your Google PageSpeed Insights score, and degrade user experience — especially on mobile and 4G connections. Google uses Largest Contentful Paint (LCP) as a direct ranking signal: compressing your hero image can bring LCP from 4 s down to under 2.5 s, directly boosting your search ranking and conversion rate.
Lossy vs lossless compression: what's the difference?
Lossy compression permanently discards some image data to achieve very small file sizes — used for JPEG and WebP. Lossless compression preserves every pixel of the original while reorganising data more efficiently — used for PNG and GIF. FileSwiftly automatically applies the appropriate method for each format. For PNG files, you can also convert to WebP via our image converter for maximum reduction.
Batch image compression with FileSwiftly Pro
The free plan compresses one image at a time up to 50 MB. FileSwiftly Pro compresses up to 50 images simultaneously, exports directly to WebP or AVIF (the next-generation format with up to 50% additional savings over WebP), lets you set a target file size in kB, and provides REST API access to automate compression in your CI/CD pipelines.
FAQ
What quality setting should I use?
75–85% is optimal for most web uses: visually identical to the original but 2–4× lighter. Below 60%, compression artefacts become visible in smooth areas like sky or gradients.
Does compression change image dimensions?
No. Compression only reduces file weight in bytes, not pixel dimensions (width × height). To resize an image, use our Image Resizer tool.
Can I compress images with transparency?
Yes. PNG images with an alpha channel (transparency) are compressed losslessly by default, fully preserving transparency. Converting to WebP also preserves transparency while achieving greater size reduction.
Which image formats are supported?
JPEG, PNG, WebP, and GIF as input. Output keeps the same format. To convert to a different format (e.g. PNG → WebP), use our Image Converter.
需要更多？
Pro版支持一次压缩50张图片
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