File Compressor
Compress files and folders into a real ZIP archive locally, with safe paths, progress, size comparison and no upload.
What Is the File Compressor?
The File Compressor packages files and folders into a standard ZIP archive entirely in your browser. It preserves safe relative folder paths, removes unsafe traversal segments, resolves duplicate names, calculates CRC checksums and uses ZIP DEFLATE compression when the browser supports it, with a standards-compliant store fallback for already-compressed or unsupported data. A file ledger shows source size, progress, archive size and actual savings before download.
How It Works
Add individual files, choose a folder or drag a group from your computer. Review the archive paths, remove anything you do not need, name the ZIP and choose the compression mode. Create the archive, compare its size with the source total and download it. The workspace caps unusually large batches to protect browser memory and never uploads file contents.
When to Use It
Use it to bundle documents for transfer, preserve a folder structure, reduce compressible text or data files, or prepare one download from several local files. JPEG, MP4, PDF and other formats that are already compressed may show little savings; Store mode is often faster for those files.
Frequently Asked Questions
- Are Files Uploaded To A Server?
- No. Reading, compression, ZIP construction and download all happen locally in your browser. The archive exists only in memory until you download it.
- Does It Create A Real ZIP File?
- Yes. The archive includes standard local headers, central directory records, UTF-8 file names, CRC checksums and either DEFLATE or stored entries so normal ZIP applications can open it.
- Why Is My ZIP Not Much Smaller?
- Photos, videos, PDFs and many office files are already compressed. Recompressing them can produce little or no reduction, while plain text, CSV, JSON and uncompressed data usually shrink more.
- Can It Protect A ZIP With A Password?
- No. This tool does not claim encryption or password protection. Use a trusted archive application that supports reviewed AES encryption when confidentiality is required.
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