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Bulk Image Compressor

Select multiple images at once and compress them all in one go. Set a single quality level for the entire batch, convert to WebP, and download each result. 100% free — your images never leave your browser.

Why bulk compression matters for websites

A single unoptimized image on a page adds 1–5 MB to the download. A product gallery with 20 such images adds 20–100 MB — enough to trigger Google's Core Web Vitals penalties and cause mobile users to leave. Bulk compression lets you process an entire product catalog, blog post library, or portfolio in minutes instead of optimizing one image at a time.

How browser-based bulk compression works

Each image is processed by JavaScript in a Web Worker-equivalent pipeline: the file is decoded into a bitmap using createImageBitmap(), drawn to a hidden <canvas> element at its original dimensions, and re-encoded using canvas.toBlob() with your chosen quality and format. The process runs in parallel using Promises, so multiple images are processed simultaneously rather than sequentially.

Privacy advantage of client-side compression

Server-based compression tools receive copies of every image you upload. With client-side processing, your images never leave your device — they're processed by your own CPU. This is especially important for confidential product photos, ID documents, and proprietary designs.

Frequently asked questions

There’s no hard limit imposed by the tool — you can select as many files as your browser can handle. However, processing very large batches (50+ large photos) may slow your browser temporarily because each image is decoded and re-encoded by the JavaScript engine. For best performance, batch in groups of 20–30 images at a time.
No. Every image is processed entirely inside your browser using the Canvas API. No data leaves your device at any point. This means bulk compression works offline once the page is loaded, and there are no file size limits imposed by server upload restrictions.
Each compressed image generates a download link as soon as it’s processed. You can download them individually. Browsers restrict JavaScript from triggering multiple simultaneous downloads automatically, so each file requires a separate click. Download them one by one from the results list.
For general web use, quality 75–82 WebP is ideal — it produces files 60–80% smaller than the originals with no visible difference at normal screen sizes. For product photography or portfolio images, use quality 85–90. For thumbnails and background images, quality 65–75 works well.