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file Utility • Zero-Server Privacy • 100% Client-Side

ZIP File Opener & Creator

Open a .zip in the browser to browse its folder tree with sizes, preview text and images, and extract one file or all of them. Or create a new ZIP from dropped files with a chosen compression level.

Overview

Opens ZIP archives in your browser and creates new ones. Browse the folder tree with file counts and sizes, filter by name, preview text and images, and extract a single file or everything into a folder you choose. Or drop files to build a new ZIP with a compression level from 0 to 9. It also opens .jar, .apk, .docx, .xlsx and .epub files, which are ZIPs inside.

How It Works

In Open mode, drop a .zip and the tool lists its contents as a collapsible tree with sizes, alongside totals for files, unpacked size and space saved. Click a file to see its size, compression method and date, with a preview for text and images, and click Extract to save it. Extract all to a folder asks for a folder and recreates the archive's structure there. In Create mode, drop files, name the archive, pick a compression level and click Create, then download the ZIP and see how much it saved.

Step-by-Step Usage Guide

  1. Choose Open to view an archive, or Create to make one.
  2. Drop the .zip file, or the files you want to compress.
  3. In Open mode, browse the tree, preview files and extract what you need.
  4. In Create mode, set the name and compression level, then click Create.
  5. Download the extracted files or the new ZIP.

Technical Specifications & Standards

Reading starts from the end of the file: the parser finds the end-of-central-directory record and reads the central directory, including ZIP64 fields for archives over 4 GB or with more than 65,535 entries. Names flagged as UTF-8 are decoded as UTF-8; others are tried as UTF-8 and then as the old DOS code page 437. Every path is cleaned before it is shown or saved. Backslashes become slashes, drive letters and leading slashes are removed, and .. segments are resolved, so a malicious zip-slip entry such as ../../etc/passwd cannot write outside the folder you chose, and the tool flags such entries. Extraction reads the local header, then copies stored data or inflates Deflate data with the browser's DecompressionStream, and checks the CRC-32 of the output, reporting a damaged archive instead of saving corrupt data. Encrypted entries and methods such as BZIP2, LZMA or Zstandard are listed but cannot be extracted. Creating archives uses JSZip, loaded only when you click Create. Extract all needs the File System Access API in Chrome and Edge.

Targeted Use Cases

  • Checking what is inside a downloaded ZIP before extracting it.
  • Pulling one file out of a large archive on a computer where you cannot install software.
  • Inspecting the contents of a .jar, .apk, .docx or .epub file.
  • Bundling several documents into one attachment for an email.
  • Spotting zip-slip paths in an archive from an untrusted source.

Notes & Gotchas

  • Use compression level 0 or 1 for photos, videos and other already-compressed files.
  • Look for the unsafe path warning before extracting archives from unknown sources.
  • Use Chrome or Edge for Extract all, which needs a folder picker.
  • Filter by name to find a file quickly in archives with thousands of entries.

Frequently Asked Questions

Can it open password-protected ZIP files?

It lists their contents, since names and sizes are not encrypted, but it cannot extract encrypted entries. Use a desktop tool such as 7-Zip with the password for those files.

Why can some files not be extracted?

They use compression methods browsers cannot decode, such as BZIP2, LZMA, XZ or Zstandard, which 7-Zip can create. The tool names the method in a warning. Standard Deflate and stored files always work.

Is it safe to open a ZIP from an unknown source?

Opening only reads the archive in your browser, and nothing is executed. Paths are cleaned so entries with ../ or drive letters cannot escape the chosen folder, and those entries are flagged.

Why does Extract all not work in my browser?

Saving many files into folders needs the File System Access API, which Chrome and Edge have and Firefox and Safari do not. In those browsers, extract files one at a time.

Are my files uploaded?

No. Archives are read, previewed, extracted and created in your browser. Large archives must fit in memory, so files over 2 GB are refused.

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