Image Compressor & WebP Converter Tool Online

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Compress JPG and PNG files, convert images to WebP, and resize oversized assets before upload. This private browser tool helps improve Core Web Vitals without sending images to a server.

Drop JPG or PNG images here or choose one or more files from your device

Privacy note: nothing is uploaded. Canvas compression happens locally.

How the Image Compressor Works

This online image compressor uses native browser features to optimize files before they reach your CMS, Astro project, or media library.

  1. Add images, drag and drop JPG or PNG files or select multiple images from your device.
  2. Choose output settings, select WebP, JPEG, or AVIF when supported, then adjust quality and optional max width.
  3. Process with canvas, each image is decoded, drawn to canvas, resized if needed, and re-encoded with canvas.toBlob.
  4. Compare savings, review original size, compressed size, percent saved, dimensions, and a preview.
  5. Download optimized files, save the compressed images and use them in your website workflow.

Why Image Compression Matters for Core Web Vitals

Images are often the largest assets on a business website. Reducing image weight can improve loading speed, user experience, crawl efficiency, and conversion rate.

  • Faster LCP, optimized hero and content images can reduce the time needed to render the largest visible element.
  • Lower bandwidth, smaller files help mobile visitors and reduce hosting transfer costs.
  • Better SEO foundations, fast pages give search engines and AI crawlers cleaner access to content.
  • Better publishing workflow, compressing before upload prevents massive original files from slowing the site later.

For a full performance workflow, pair this compressor with our Image SEO Checker and Core Web Vitals guide.

Image Format Reference

Choose the format based on the image type, required browser support, and publishing workflow.

FormatBest useBrowser support note
WebPMost website photos, product images, and blog graphicsBroad modern browser support and strong compression.
JPEGMaximum compatibility for photos without transparencyUniversal support, but larger than WebP at similar quality.
PNGLogos, UI assets, screenshots, and transparent graphicsLossless and widely supported, but can be large for photos.
AVIFModern high-compression image deliveryExcellent compression, but canvas export support varies by browser.

Compression Best Practices

  • Resize huge camera photos before adding them to the website.
  • Use WebP for content images and keep PNG for logos or graphics that need crisp transparency.
  • Keep width and height attributes in HTML to prevent layout shift.
  • Use descriptive filenames and alt text after compression so image SEO is not lost.
  • For Astro projects, store content images in src/assets/ and use the Astro Image component for final build optimization.

Image Format Reference

Picking the right format is the first speed win. Match the format to the content, then compress. For a complete image pipeline across your site, see our website speed and performance optimization service.

Format Best for Notes and typical savings
JPEG Photographs and complex images without transparency Universal support; larger than WebP and AVIF at similar quality.
PNG Transparency, flat graphics, logos, and screenshots Lossless and crisp, but heavy for photos; prefer for flat or transparent art.
WebP Modern all-round choice for most website images Broad support; typically around 25 to 35 percent smaller than JPEG at similar quality.
AVIF Maximum compression for modern browsers Best compression of the common web formats; provide a fallback for older browsers.
SVG Vector graphics: logos, icons, and simple illustrations Scales without quality loss and is usually tiny; not for photos.

Savings figures are typical ranges and vary with image content, dimensions, and quality settings. A reliable order of preference for photos is AVIF, then WebP, then JPEG, with PNG reserved for flat or transparent graphics and SVG for vectors.

Next steps

Image Compressor related tools and articles

Continue with the closest follow-up checks and guides based on this tool's topic, crawl intent, and optimization workflow.

Image Compressor: FAQ

Which source files can this compressor process?
The file picker and drop handler accept JPEG and PNG images. You can select multiple files, and the tool processes them one at a time into separate WebP, JPEG, or supported AVIF downloads.
How does Max width change the image?
If the source is wider than the entered maximum, the canvas scales both dimensions down proportionally. Smaller images are not enlarged. A blank or zero-like value keeps the source width.
What does the quality setting control?
The selected value is passed to the browser's canvas encoder for WebP, JPEG, or AVIF. Lower values often reduce size but can introduce artifacts, and different browsers or formats may interpret the same value differently.
Why is AVIF unavailable in the format list?
The tool tests whether the current browser can export an AVIF blob from canvas. If that test fails, AVIF is hidden and disabled. Browser support for viewing AVIF does not necessarily mean canvas encoding is available.
What does the saved percentage mean?
It compares the generated blob size with the original file size. A negative saving is shown as a percentage larger, which can happen with already optimized images, small graphics, or an unsuitable output format.
What happens to PNG transparency when I choose JPEG?
JPEG has no alpha channel, so the tool paints a white canvas before drawing the source. WebP and AVIF can preserve transparency when the browser's encoder supports it.
Are metadata and animation preserved?
Do not assume so. Re-encoding through canvas typically discards EXIF and other embedded metadata, and this tool accepts only JPEG or PNG rather than animated GIF. Keep originals and verify orientation, color, and transparency before publishing.
Are selected images uploaded to Web Aloha?
No. Image decoding, resizing, encoding, previews, and download blobs are created in your browser. The selected files are not sent to a Web Aloha endpoint by this tool.

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