ZIP to 7Z Converter

1. Upload your ZIP file (up to 500 MB).
2. Click 'Convert ZIP to 7Z' — takes 20 seconds to 5 minutes.
3. Download the smaller 7Z archive.

7Z (7-Zip) achieves 30-70% better compression than ZIP thanks to the LZMA2 algorithm. Converting a ZIP to 7Z can shrink it significantly — perfect for archiving and storage.

ZIP is the most universal archive format, but it uses the older Deflate compression algorithm. 7Z (7-Zip) uses LZMA2 — much more efficient, achieving 30-70% better compression on typical archives. Converting ZIP to 7Z is a free way to reduce storage size without losing any data.

The converter reads the ZIP archive, extracts all files, and re-compresses them using LZMA2 into a 7Z archive. File structure, timestamps, and permissions are preserved. Output is a standard 7Z file.

• Reducing ZIP archive size for storage.
• Archiving files with better compression than ZIP.
• Reducing upload size for file transfer services.
• Optimizing backups with 7Z compression.
• Preparing archives for cloud storage.
• Shrinking ZIP archives before emailing.
• Maximizing compression for archival storage.

7Z conversion is fully lossless — every file is preserved byte-identically. The only difference is the compression algorithm, which achieves 30-70% smaller archives for typical file collections.

• 7Z is less universal than ZIP — some systems only support ZIP.
• Encrypted or password-protected ZIPs can't be converted.
• Multi-part ZIPs are not supported.
• Very large archives (>500 MB) aren't supported.
• Compression takes time — larger archives take minutes.

• Output 7Z opens with 7-Zip, WinRAR, PeaZip, and most modern tools.
• Windows 11 supports 7Z natively (since 2023).
• macOS supports 7Z with The Unarchiver or Keka.
• Linux supports 7Z with p7zip.
• Standard 7Z — no special software needed on modern systems.

• 7Z is 30-70% smaller than ZIP for typical archives.
• Fully lossless — every file preserved byte-identically.
• For maximum compatibility, keep the original ZIP.
• Encrypted ZIPs must be unlocked first.
• Batch-convert up to 500 MB at once.

7Z doesn't open on some systems

Some older systems only support ZIP. 7-Zip, WinRAR, and Windows 11 (2023+) support 7Z natively.

Conversion fails with encrypted ZIP

Encrypted or password-protected ZIPs must be unlocked first.

Compression is slow

LZMA2 is CPU-intensive. Larger archives take 1-5 minutes. The result is worth it — 30-70% smaller.

• 7-Zip — Official
• PKWARE — ZIP Specification