Apchukso ~/zip● No upload · No install
Photos, videos, and HWP (Hancom Office) documents are already compressed, so zipping them again barely changes the size. To reduce ZIP file size, drop in a ZIP: Apchukso shrinks the photos, PDFs, and HWP files inside one by one, then re-zips them at maximum compression.
Each split ZIP opens on its own, so recipients don't need to put the parts back together.
If you've ever zipped files only to find the size barely changed, nothing's broken. Photos (JPG), videos (MP4), and HWP documents are already compressed when they're saved, so zipping them again leaves almost no room to shrink. The same goes for ALZip, Bandizip, and Windows' built-in compression.
| File | Original | After zipping | Reduction |
|---|---|---|---|
| 3 phone photos (JPG) | 19.72MB | 18.04MB | 8.6% |
| Video (MP4, 1080p, 52 s) | 74.46MB | 74.43MB | Under 0.1% |
| HWP press release (8 photos) | 23.10MB | 22.95MB | 0.7% |
| 3 PDF press releases (government briefings) | 2.74MB | 2.56MB | 6.8% |
| Text (TXT) | 115.0KB | 43.6KB | 62.1% |
These are measurements with Bandizip's default compression. Only files that weren't compressed much inside, like plain text, shrank a lot, while the video and the HWP file full of photos shrank by less than 1%. Even three phone photos together shrank by only 8.6%. So to reduce the size, you don't change how you zip. You shrink the size and quality of the photos inside the files, and that's exactly what this tool does.
If re-saving doesn't make a file more than 5% smaller, the original goes in as is. The folder structure and filenames stay the same, and only junk files are removed, such as the __MACOSX folder that macOS slips in, .DS_Store, and Thumbs.db.
| Level | Photos | Images in PDFs | Images in HWP files |
|---|---|---|---|
| Strong | About 1.9M pixels (1,600×1,200) · Quality 72% | 72dpi | 120dpi |
| Recommended | About 4.9M pixels (2,560×1,920) · Quality 82% | 150dpi | 200dpi |
| Light | About 11M pixels (3,840×2,880) · Quality 90% | 300dpi | 300dpi |
If a photo is already smaller than the target size, its dimensions stay the same and only the quality is adjusted. PNGs are reduced to 256 colors at Strong and Recommended; at Light, colors aren't reduced.
| Input ZIP | Original ZIP | New ZIP (Recommended) |
|---|---|---|
| Photo set: 3 phone photos, 1 screenshot, a note | 20.45MB | 2.55MB |
| Press release set: 3 HWP press releases, the same 3 as PDFs, 2 event photos, a note | 51.49MB | 3.82MB |
| Field report set: 4 photos, a PDF, 3 HWP files, a video, a note | 55.41MB | 22.55MB |
Results from Chrome on a PC in October 2026. Each set took 4–45 seconds depending on the number and type of files, and every compressed HWP file kept the same page count and text as the original. In the press release set, a 23.10MB HWP press release became 731.5KB and a 7.83MB photo became 479.7KB, for a 93% reduction overall. In the field report set, the video added as is (13.94MB) makes up most of the new ZIP. The same set came to 18.84MB at Strong and 29.81MB at Light. This ZIP had Korean names written in the old encoding (CP949), but in the new ZIP the names didn't break in either Bandizip or Windows' built-in extractor.
Q. I zipped my files. Why is the size about the same?
Photos (JPG), videos (MP4), and HWP documents are already compressed when saved, so zipping them again leaves almost no room to shrink. When we measured with Bandizip, a video shrank by less than 0.1%, an HWP press release full of photos by 0.7%, and three phone photos by 8.6%. To reduce the size, you need to shrink the size and quality of the photos inside the files, not change how you zip them.
Q. How much does photo quality drop?
Recommended fits photos to about 4.9M pixels (2,560×1,920) and re-saves them at 82% quality. On a phone or computer screen, the difference is hard to spot. For photos you'll print large, choose Light (about 11M pixels, 90% quality). Files that wouldn't get more than 5% smaller are left untouched and added as originals.
Q. What happens to photo metadata?
Re-saved photos lose info such as the date taken, phone model, and location (GPS). That's reassuring if you're sending photos to others, but if you need this info, keep the originals separately. Files added untouched keep their info.
Q. Can I split it to fit email attachment limits?
Yes. Under "Split into parts," choose 10MB, 20MB, 25MB, or any size you like, and the result is split into several ZIPs that stay under that size. Each split ZIP is a complete ZIP that opens on its own, so recipients don't have to put the parts back together. If a single file is bigger than the size you chose, it goes into its own ZIP and you'll be told.
Q. Does it compress videos, too?
This tool adds videos as is. Compress them separately with Apchukso's Compress video, then add them along with your other files.
Q. Does it work with password-protected archives or RAR/7Z?
Password-protected ZIPs and RAR, 7Z, and ALZ files aren't supported yet. ALZip EGG files (.egg) work right away if they have no password. If they do, enter the password in the EGG extractor (Korean page), download the result as a ZIP, and add that.
Q. Will Korean filenames get garbled?
Korean names written by older Windows ZIP programs (CP949) are read correctly, and the new ZIP stores names in today's standard (UTF-8). The folder structure and filenames stay the same.
Q. Are my files uploaded to a server?
No. Extracting, compressing, and re-zipping all happen inside this browser. If there are PDFs or HWP files, a processing engine is downloaded once, the first time, but your files are never sent anywhere.