Core features

Open, inspect and extract archive files

Open A Zip lets you browse folders inside an archive, preview supported files and extract only what you need.

Open ZIP files onlineUse it as a ZIP opener, file unzipper and ZIP file extractor in the browser.

Browse archive contentsSee folders, file types and sizes before downloading anything.

Extract selected filesDownload individual files instead of extracting the whole archive.

RAR, 7Z and split archive supportOpen ZIP, RAR, 7Z, TAR.GZ and multi-part archives without uploading them.

Preview before extract

Preview files inside archives

Preview documents, images, media, code and data files directly from inside an archive — no extraction needed.

1 export const archive = { 2 name: 'project-assets.zip', 3 preview: true, 4 extract: 'selected-files' 5 };

Supported previews

See what is inside before you extract

Preview common documents, media, data files and nested archives directly from the archive file list.

DocumentsPDF, DOCX, XLSX and EPUB

ImagesJPG, PNG, WEBP, HEIC, AVIF, TIFF, PSD and RAW photos

MediaMP3, WAV, FLAC, MP4, WEBM and MOV

Data, code and nested archivesTXT, HTML, XML, JSON, CSV, TSV, Markdown, source code, and ZIP, RAR, 7Z or TAR.GZ files inside another archive

Private by design

Unzip files without uploading

No uploadsArchive files are processed locally in your browser.

No signupNo account or login required. Just drop a file.

Passwords stay localPasswords are used on your device to open encrypted archives.

Built for local previewPreview archive contents before choosing what to extract.

Format support

Supported archive formats

Common archivesZIP, ZIPX, RAR, 7Z

Unix archivesTAR, TAR.GZ, TGZ, GZ, BZ2, XZ, ZST, LZ4

Package and disk formatsISO, CAB, CPIO, DEB

Split archive parts.001, .z01, .r00 and related parts

Under the hood

How the extraction engine works

Open A Zip uses WebAssembly-compiled decoders running inside your browser — no server-side processing.

7-Zip LZMA SDK via WebAssembly The core decoder is compiled from the 7-Zip C SDK to WASM, supporting LZMA, LZMA2, PPMd, BZip2, Deflate, and Deflate64 compression methods natively.

BCJ/BCJ2 filter chains Executable filters (x86, ARM, ARM64, PowerPC, SPARC) are applied in-pipeline before decompression, matching desktop 7-Zip behavior.

AES-256 decryption in WASM Password-protected ZIP (AES-256) and RAR5 archives are decrypted entirely within the WebAssembly sandbox. Your password never leaves the browser.

Streaming with File.slice() Large files are read in chunks via the File API's slice method, enabling partial reads without loading the entire archive into memory at once.

File System Access API On Chromium 86+ browsers, extracted files are written directly to your local disk via the File System Access API — no intermediate Blob download required.

Worker-based parallelism Decoding runs in a dedicated Web Worker thread, keeping the UI responsive even for archives with thousands of entries or heavy compression.

Transparency

Known limits and troubleshooting

Open A Zip runs entirely in your browser. Here is what that means in practice.

Browser memory is the ceilingVery large archives (typically over 2 GB uncompressed) may exhaust available memory depending on your device and browser.

All split parts must be presentMulti-part archives (.001/.z01/.r00) require every part to be selected together. Missing parts will cause an incomplete read.

Some rare methods are unsupportedExotic compression or encryption variants (e.g. legacy Implode, LZFSE-only, or proprietary DRM) may not open.

Damaged files may failIf an archive was partially downloaded or corrupted in transit, extraction can fail or produce incomplete results.

Common failure scenarios

"Cannot open archive": Usually means the file is damaged or truncated. Re-download and verify the file size matches the original.
"Wrong password" on a correct password: The archive may use an encryption method not yet supported. Try re-exporting the archive as standard AES-256 ZIP or RAR5.
Browser becomes slow or unresponsive: The archive is too large for available memory. Close other tabs, try a desktop browser, or extract in smaller batches.
Missing files after opening a split archive: Not all volume parts were selected. Re-open and select every .001/.002/... or .z01/.z02/... file together.

How it works

How to unzip files online

Choose or drop a ZIP, RAR, 7Z or TAR.GZ file.
Browse files and folders inside the archive.
Preview supported files before extracting.
Select files and extract or download what you need.

FAQ

Common questions

Are my files uploaded?

No. Files are processed locally in your browser.

Can I use Open A Zip to extract ZIP files online?

Yes. You can open ZIP files, preview contents and extract selected files online.

Does it work as a RAR opener or RAR extractor?

Open A Zip supports common RAR archives along with ZIP, 7Z and TAR.GZ files.

What's the maximum file size?

Open A Zip runs in your browser, so the practical limit depends on available memory, browser limits and archive complexity.

Does it support password-protected archives?

Yes. You can enter archive passwords locally to open supported encrypted ZIP, RAR and 7Z files.

What file types can I preview inside an archive?

You can preview documents, images, audio, video, text, code, CSV/TSV, Markdown, JSON, XML, HTML, EPUB and nested archives before extracting.

Why does an archive fail to open?

Common causes include incomplete downloads, missing split-archive parts, unsupported compression methods, or file corruption. Re-download the file and verify all parts are present.

What should I do when extraction fails?

Close other browser tabs to free memory, ensure all split parts are selected, and try again. If the issue persists, the archive may be damaged or use an unsupported format variant.