ZIP File Inspector
Browse any ZIP archive online for free — without extracting a single file. Our ZIP file inspector reads the archive's central directory entirely in your browser and shows you every file's name, size, compression ratio, and method in a sortable, searchable table. No signup required.
Why Use Our ZIP File Inspector?
Instant ZIP Inspection
Browse any ZIP archive in seconds. Our ZIP file inspector reads the central directory entirely in your browser — no extraction, no wait, no server round-trip.
Secure ZIP File Inspector Online
Your ZIP file never leaves your device when you inspect it. 100% client-side processing means complete privacy — no cloud storage, no server logs, no data exposure.
ZIP File Inspector Online — No Installation
Inspect ZIP archives directly in your browser. No software downloads, no plugins, no account required. Works on any modern browser on any operating system.
Sortable, Searchable File Table
Search by filename, sort by size or compression ratio, filter out folders, and see per-file compression stats — all in a clean, responsive table with no file size limits.
Common Use Cases for ZIP File Inspector
Security Auditing Before Extraction
Inspect a ZIP archive before extracting to check for path traversal attacks (e.g. files with "../" in their names) or unexpectedly large files that could fill your disk.
Build Artifact Verification
Verify that a CI/CD build artifact ZIP contains the expected files and directory structure before deploying — without extracting the entire archive to a staging environment.
Archive Content Auditing
Audit the contents of a ZIP backup or data export to confirm all expected files are present and check their sizes match the source — without downloading and extracting gigabytes of data.
Debugging Compression Issues
Identify files stored with method "Stored" (0% compression) inside a ZIP that should be compressed, or find oversized files that are inflating your archive size.
Package & Dependency Inspection
Inspect npm packages (.tgz), Java JARs, Python wheels (.whl), and other ZIP-based package formats to see their internal structure and file sizes before installing.
Document Archive Review
Browse the contents of DOCX, XLSX, PPTX, and other Office Open XML files (which are ZIP archives) to inspect embedded resources, images, and XML components.
Understanding ZIP File Inspection
What is ZIP File Inspection?
ZIP file inspection is the process of reading a ZIP archive's central directory— a structured index stored at the end of every ZIP file — to enumerate its contents without decompressing any data. Every ZIP archive contains a central directory that lists every file's name, path, compressed size, uncompressed size, compression method, and last-modified timestamp. Our ZIP file inspector reads this directory entirely in your browser using JSZip, so you can browse the full contents of any ZIP archive instantly without extracting a single byte to disk.
How Our ZIP File Inspector Works
- 1Upload your ZIP file: Drag and drop any ZIP archive onto the drop zone, or click to browse. The file is read directly in your browser — nothing is uploaded to any server.
- 2Instant browser-based parsing: The ZIP central directory is parsed immediately using JSZip. All file metadata is extracted from the archive headers — no decompression occurs, so even large archives load in milliseconds.
- 3Browse, search, and sort: Explore the full file tree, search by filename or path, sort by size or compression ratio, and filter out directory entries — all without extracting anything.
What Information Is Shown
- File Name & Path: The full path of every file and folder inside the archive, preserving the original directory hierarchy.
- Original Size: The uncompressed size of each file — what it will occupy on disk after extraction.
- Compressed Size: The actual size each file occupies inside the ZIP archive after compression.
- Compression Ratio: The percentage of space saved by compression, calculated as
(original − compressed) / original × 100. Files stored with method "Stored" show 0%.
ZIP Formats That Are Supported
Our ZIP file inspector supports standard ZIP archives created by any tool — including Windows Explorer, macOS Finder, 7-Zip, WinRAR, Info-ZIP, and programmatic tools like JSZip, Python's zipfile, and Java's ZipOutputStream. It also works with ZIP-based formats like DOCX, XLSX, PPTX, JAR, APK, and Python wheel (.whl) files — just rename them to .zip or drop them directly. ZIP64 archives (files over 4 GB) are supported in modern browsers.
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Frequently Asked Questions About ZIP File Inspector
A ZIP file inspector is a tool that reads the contents of a ZIP archive and displays file names, sizes, and compression ratios without extracting any files. Our free ZIP file inspector online works entirely in your browser using JSZip — your archive is never uploaded to any server.
No. Our ZIP file inspector only reads the central directory metadata stored inside the archive. No files are extracted, no data is decompressed to disk, and the original ZIP file is never modified. It is a completely read-only, non-destructive operation.
Absolutely. Our ZIP file inspector processes everything locally in your browser using JSZip. Your archive is never uploaded to any server, never stored, and never leaves your device. All parsing happens entirely on your machine for complete privacy.
Yes — 100% free, forever. No signup, no account, no premium tier, no file size limits, and no ads interrupting your workflow. Just drop your ZIP and browse.
The compression ratio shows the percentage of space saved by compression for each file, calculated as (original size − compressed size) / original size × 100. A ratio of 70% means the file is 70% smaller inside the ZIP than it would be uncompressed. Files stored with method "Stored" show 0% because they are included without compression.
Yes. DOCX, XLSX, PPTX, JAR, APK, .whl (Python wheel), and many other formats are ZIP archives with a different extension. You can drop them directly into the inspector — it will parse them correctly and show all internal files and their sizes.
Deflate is the standard ZIP compression algorithm — files compressed with Deflate are smaller inside the archive. Stored means the file was added to the ZIP without any compression, so its compressed size equals its original size. Already-compressed files (JPEG, PNG, MP3) are often stored rather than deflated because they cannot be compressed further.
Since inspection runs entirely in your browser, the practical limit depends on your device's available RAM. Most modern devices handle ZIP archives up to several hundred MB without issues. For very large archives (1 GB+), ensure you have sufficient memory available.
Files with 0% compression ratio are stored using the "Stored" method — they are included in the ZIP without compression. This is common for already-compressed formats like JPEG, PNG, MP3, MP4, and PDF, where applying DEFLATE compression would not reduce the size and would only slow down extraction.