Compress Images for Website Faster Pages, Better Core Web Vitals
Oversized images are the #1 cause of slow websites. CompressVault converts JPEG and PNG to WebP or AVIF — the formats Google recommends — and compresses them privately in your browser.
Compress images for my websiteConvert to WebP or AVIF
WebP delivers 25–35% smaller files than JPEG. AVIF pushes it further — 40–50% smaller. Both are fully supported by modern browsers and recommended by Google PageSpeed.
Improve Core Web Vitals
Smaller images mean faster Largest Contentful Paint (LCP) — a direct Google ranking factor. Optimized images are the single highest-impact improvement for most websites.
Batch Process Entire Libraries
Drop your entire image folder at once. Compress and convert dozens of images in a single session, then download the ZIP ready for deployment.
Target file sizes for common web image types
- Hero / banner images — aim for under 400 KB (WebP at 80% quality is typical)
- Product images — 50–150 KB per image in WebP or AVIF
- Blog post inline images — 80–200 KB
- Thumbnails and avatars — under 30 KB
- Background images — under 100 KB; consider CSS gradients instead where possible
- Google PageSpeed Insights flags images that could be reduced by more than 25 KB
Optimize images for the web
- 1
Upload your site images
Drop JPEG, PNG, or WebP files — single images or entire batches. Your files are loaded directly into your browser's memory.
- 2
Convert format and set quality
Choose WebP or AVIF as the output format. Adjust quality to balance file size and visual sharpness. See the compressed size instantly before downloading.
- 3
Download and deploy
Download individual images or the full ZIP. Drop the optimized files into your site's assets folder and watch your PageSpeed score improve.
Zero uploads, zero tracking
CompressVault runs 100% in your browser using the Canvas API. Your images are never sent to any server — not even ours. No account required, no usage limits, no ads.
What's the highest-impact image change you can make for site speed?
For most websites, the single biggest performance lever is converting hero JPEGs and PNGs to WebP or AVIF. Google has been pushing both formats for years because the savings are dramatic at the same perceived quality: WebP typically lands 25 to 35 percent smaller than equivalent JPEG, and AVIF often shaves another 40 to 50 percent on top of WebP. Browser support is no longer a barrier — every major engine has shipped WebP since 2020 and AVIF since 2022. If your site still ships JPEGs above the fold, you are leaving the easiest performance win on the table.
Image weight feeds directly into Largest Contentful Paint, the Core Web Vital that measures when the biggest above-the-fold element finishes rendering. LCP is one of the signals Google uses for search ranking, and it is dominated by hero images on most marketing pages. Cutting your hero from 800 KB to 250 KB doesn't just improve a score in PageSpeed Insights — it shaves real seconds off how long visitors wait for content on slow mobile connections. Compressing and converting a single hero image is often the difference between a green and a red Web Vitals report.
The trick with web images is matching the format and quality to the role each image plays. Hero banners benefit from WebP at 80 to 85 percent quality and a width that matches your largest layout breakpoint. Product thumbnails can drop to 60 to 70 percent and 200 to 400 pixels wide. Inline blog images sit comfortably at 75 percent and 800 pixels wide. CompressVault lets you set quality and dimensions per file, see the projected output size before you commit, and batch-process an entire content folder in one session.
Once your assets are optimized, pair them with HTML srcset and the picture element so each device downloads only the size it needs. CompressVault produces clean, metadata-free output that drops straight into a static asset pipeline, a CMS upload form, or a CDN bucket. Because everything runs locally there are no per-image fees, no account quotas and no API rate limits to design around — you can re-encode an entire image library overnight without touching a credit card. That makes ongoing optimisation a habit instead of a quarterly project.
Frequently Asked Questions
What image format is best for websites?
WebP and AVIF are the best formats for websites in 2024. WebP delivers 25–35% smaller files than JPEG at equivalent quality, while AVIF achieves 40–50% reduction. Both formats are supported by all major modern browsers. CompressVault can convert JPEG and PNG to either format.
How do large images affect Core Web Vitals?
Oversized images are the leading cause of poor Largest Contentful Paint (LCP) scores — one of Google's Core Web Vitals signals used in search ranking. Compressing and converting images to WebP or AVIF can dramatically improve LCP and your overall PageSpeed Insights score.
What quality setting should I use for web images?
For most web images, a quality of 75–85% in JPEG or 70–80% in WebP provides excellent visual fidelity at significantly reduced file sizes. Hero images and product photos may warrant 85–90% quality, while thumbnails can use 60–70%.
Should I serve different image sizes for mobile and desktop?
Ideally yes — this is called responsive images. Use the HTML srcset attribute to serve different sizes. CompressVault lets you resize images by dimension while compressing, so you can generate multiple size variants for the same image.
Is there a recommended maximum file size for website images?
Google recommends keeping images under 200 KB for most use cases. Hero images can go up to 400–500 KB if they're above the fold. Background images should target 100 KB or less. With WebP conversion in CompressVault, most JPEG photos hit these targets comfortably.
Ready to compress your images?
Free, private, and unlimited — no sign-up needed.
Compress images for my website