Compress Images in Bulk

Batch compression is mostly a memory-management problem. A single 24-megapixel photo occupies about 96 MB of RAM once decoded, since every pixel expands to 4 bytes. Decode 200 of them simultaneously and any laptop falls over. So this tool runs a small pool of workers - typically two to four files in flight at a time - keeping throughput high while memory stays flat. The progress list shows exactly which file is being crunched at any moment.

Uniform settings across wildly different images is the usual batch dilemma. Quality 80 is a sensible universal default: photographs compress well there, and graphics survive it. Mixed batches with screenshots benefit from choosing WebP output, which handles both photographic and flat content gracefully. If a handful of files matter more than the rest, run those individually afterward with tailored settings - batches are for the ninety percent that just need to be smaller.

Results arrive as a ZIP with the original filenames preserved, so references from HTML, spreadsheets or DAM systems keep working after you swap the folder contents. Files that end up larger after compression - it happens with already-optimized images - are copied through unchanged rather than bloated, and the summary line totals your savings across the whole run.

A note on scale: since everything executes in one browser tab, extremely large runs are bounded by patience more than by rules. A thousand phone photos take a few minutes on a modern machine. If a tab is killed mid-run by the OS, split the job into two smaller batches; nothing is lost, because your originals were never modified.