- Browsers have limited access to the local filesystem for security reasons. This is to protect users from potentially malicious websites accessing or modifying files on their computers without permission.
- Modern browsers can read local files and directories, but true write access (beyond just downloading files) is more restricted.
- The File System Access API, available in some modern browsers, allows web applications to interact with files on the user's local device, but with important security measures in place:
- The user must explicitly grant permission through a file picker dialog.
- Access is limited to specific files or directories chosen by the user.
- Permissions are typically not persistent and are lost when the browser is closed.
- Browsers generally do not allow arbitrary access to the entire filesystem. For example, a web page cannot freely browse or access files outside of specifically granted locations.
- When opening local HTML files directly (using the file:// protocol), browsers often impose additional restrictions on JavaScript execution and file access to prevent potential security risks.
- Some organizations may further restrict local file access in browsers for security reasons, especially in shared or managed environments.
In summary, while browsers can access some parts of the local filesystem under specific circumstances and with user permission, they do not have unrestricted access to the client's entire filesystem. This limited access is a crucial security feature to protect users from unauthorized file access or manipulation by web applications.