ClientSideTools Privacy-First Browser Tools

OPFS (Origin Private File System) Explorer

The Origin Private File System gives WASM, SQLite-in-browser, and offline apps a fast, private file store — but there's no way to browse it. This explorer lists every directory and file in your origin's OPFS, with sizes, types, and in-place reading.

PWA & Browser Storage Local processing Files stay in the origin sandbox. Nothing is uploaded.

Tool interface

Exploring OPFS for origin:

Introduction

OPFS is a high-performance, origin-scoped file system used by WASM apps, in-browser databases, and offline tools. Because it's invisible to normal file pickers, developers have no way to inspect what's stored. This explorer fills that gap.

How it works

  • Opens the OPFS root via navigator.storage.getDirectory().
  • Recursively walks directories with FileSystemDirectoryHandle.values().
  • Reads file size and type via FileSystemFileHandle.getFile().
  • Renders an expandable tree and lets you read small text files in-place.

Privacy

All reads happen inside the origin's sandbox via the File System Access API. Files never leave the browser. No account, no API key.

Limitations

  • Files over 1 MB are not read in-place.
  • OPFS requires a secure context and modern browser support.
  • Cannot access OPFS from other origins.

FAQ

What is OPFS?

The Origin Private File System is a private, origin-scoped file store optimized for high-performance reads/writes, commonly used by WASM and SQLite-in-browser apps.

Are my files uploaded?

No. Everything is read locally inside the origin sandbox.

Related tools

Version and changelog

  • Version: 1.0.0
  • Last updated: August 12, 2026
  • Changelog: Initial production release.