Frequently Asked Questions

Absolutely not. All of Compressvip's compression runs entirely in your browser — your image files never leave your computer from start to finish. You can press F12 to open the developer tools' "Network" panel and verify: the number of requests to any server during compression is 0. All our compression happens locally in your browser using native browser encoding; your images never leave your device, and there is no need to hand files over to any remote server.

Very safe. Our core design philosophy is "local-first, privacy-first": ① files are never uploaded, everything is processed in the browser; ② we do not integrate third-party tracking scripts like Google Analytics; ③ we do not load resources from external CDNs; ④ we do not require registration or login, and we do not collect personal information. The only thing stored locally in your browser is your chosen theme preference and language setting, which live solely in your own browser's localStorage and which we cannot access.

Yes, Compressvip is always free. There is no "3 free uses per day, pay for unlimited" restriction, no registration gate, no watermark-on-export trick. Whether you compress 1 image or 1000, the features are identical and all free. We believe good tools should be open to everyone without paywalls. If there are any future monetization changes, we will announce them in advance and provide ample transition time.

We currently support six major image formats: JPG/JPEG, PNG, WebP, AVIF, GIF, and SVG. Compression runs locally in your browser, using Canvas encoding combined with quality optimization strategies to reduce size — your images never leave your device. You can also convert images to other formats while compressing, such as turning PNG into WebP for better compression.

It depends on the compression strength you choose. Our quality slider ranges from 1 to 100, and the default value typically reduces file size significantly while keeping quality loss nearly imperceptible to the eye. For JPEG, a quality of 75-85 usually reduces file size by 60%-80% with almost no visible difference. For scenarios demanding maximum quality (such as photography), raise quality above 90; for web display, 60-70 delivers acceptable results. The real-time preview lets you compare before compressing.

Yes. Compressvip supports batch processing: drag multiple images into the upload area, click to select multiple images, or even drag an entire folder in. Each image can have its own compression settings (format, quality, size), and you can also use "Apply to All" for one-click unified settings. After processing you can download images one by one, or download all results as a single ZIP. The whole batch process is pure local processing with no concurrency limits.

Yes. Besides compressing file size, you can also adjust pixel dimensions. We offer: scaling by percentage (e.g. shrink to 50% of the original), specifying pixel values by width/height (auto-maintaining aspect ratio), and preset common sizes (such as 400×400 social media avatars, 800×800 marketplace main images). Resizing and compression happen together without extra quality loss.

Absolutely. Compressvip is a responsive website that runs smoothly on iOS Safari and Android Chrome. On mobile you can: select photos from your gallery, take a photo and compress it directly, and drag files (supported by some browsers). All compression runs locally in your mobile browser with good performance. You can also add the site to your home screen and open it like a shortcut anytime.

SVG is a vector format, and its compression differs from bitmap formats (JPG/PNG). We optimize SVG locally by removing comments, removing editor metadata (such as extra info generated by Illustrator or Figma), and stripping XML declarations and redundant whitespace between tags. These are all lossless operations — the SVG renders exactly the same while the file size shrinks.

WebP and AVIF are next-generation image formats with far better compression than traditional JPG and PNG:

• WebP: a format by Google that is 25%-35% smaller than JPG and 30%-50% smaller than PNG at the same quality. It supports lossy/lossless compression, transparency, and animation, and is supported by all major browsers.
• AVIF: based on the AV1 video codec, compresses even better than WebP, being over 50% smaller than JPG at the same quality. It supports HDR, wide color gamut and transparency — the newest generation image format with over 90% browser support.

If you care about load speed and bandwidth, we strongly recommend converting images to WebP or AVIF.

Zero seconds. Your files never leave your browser in the first place, so there is no question of "how long they stay on a server." Compression happens in browser memory, and all data is automatically cleared once you close the tab. No file upload, no cloud storage, no temporary cache servers. This is the full meaning of "zero upload" — not "upload then delete immediately after compressing," but "there is no upload step at all."

You are welcome to reach us through: ① submitting an Issue on GitHub (the project is fully open source, link at the bottom of the site); ② emailing our technical support address (see footer). When submitting feedback, please include: the browser and version you use, your operating system, the image format and approximate file size, and the specific symptom or error message. This helps us locate and resolve issues faster.