How many images can I compress at once?
The honest answer isn't a single number — it depends on your device. Our bulk compressor doesn't impose a hard cap because it runs entirely in your browser, so the limit is set by your device's memory rather than any tool policy. Here's what works in practice.
Practical batch sizes by device
| Device class | Safe batch size | Absolute ceiling |
|---|---|---|
| Modern laptop (8+ GB RAM) | 200–500 | ~1000 |
| Older laptop (4 GB RAM) | 50–150 | ~300 |
| iPhone 13+ / Android flagship | 30–80 | ~150 |
| Older phone (iPhone 8, older Android) | 20–30 | ~50 |
Why there's no hard cap
Every server-based bulk compressor imposes a cap because uploading and processing large batches costs the provider money. Our tool doesn't upload anything — the compression happens on your device via the browser's Canvas API. There's no server, no per-compression cost, and no reason to count.
The real constraint is your browser tab's memory. Every compressed file is held as a Blob in memory until you either download it or clear the queue. Once your accumulated queue approaches a gigabyte or two, the browser starts pushing back.
What to do for very large batches
For jobs of 1000+ files, the reliable pattern is:
- Drop the first 200 files, wait for them to process, download the ZIP.
- Hit "Clear all" — this frees the memory held by the finished blobs.
- Drop the next 200 files, repeat.
Total wall-clock time for a 1000-file batch: about 15 minutes on a modern laptop, spread across five browser sessions. That's slower than a paid server-based tool would manage, but faster than waiting for an upload-download round-trip on a mobile connection — and every file stays on your device.
Comparison to popular alternatives
Where the free tiers of well-known bulk compressors cap you:
- TinyPNG free: 20 files per batch, 5 MB per file, 500 compressions per month.
- ILoveIMG free: 15 files per batch, 40 MB total per batch.
- Compressor.io free: 10 MB per file, no batch mode.
- Squoosh: single file only; no batch mode.
- Image-Compressor.uk (this site): no batch cap, no monthly cap, 25 MB per individual file, everything client-side.
Try it
Head to the bulk image compressor and drop whatever you've got. The queue tracks progress per file so you can see if you're approaching the browser's limit. If your first batch runs smoothly, add more files.