SmartProxy

SmartProxy is a free, open-source browser extension that automates proxy selection based on user-defined rules, eliminating the need to manually switch proxies when visiting different sites. Instead of manually toggling a proxy on and off as you move between sites that require proxying and sites that don't, SmartProxy watches each request and automatically uses the appropriate proxy based on patterns you define. The extension is published on GitHub under an open license, with versions available for Firefox, Chrome, and Edge.

The fundamental use case SmartProxy addresses is automation. Many users find themselves proxying certain sites or certain activities but not others. A developer might proxy requests to internal company servers but access public resources directly. A researcher might proxy requests to one set of domains for one project and other domains for another project. A tester might rotate between different proxy configurations for different test scenarios. Without automation, this requires constantly switching proxy settings or using separate browser windows, each a manual and error-prone process. SmartProxy automates it through pattern-based rules.

Rules in SmartProxy work by URL pattern matching. A user defines patterns using wildcards or regular expressions and assigns each pattern to a proxy or proxy group. When a request matches a pattern, SmartProxy automatically routes it through the associated proxy. Patterns can be as simple as matching an exact domain like example.com, or as complex as matching any path matching a regular expression across multiple domains. The rules are stored in the browser's local storage, persisting across browser restarts and available even when offline.

SmartProxy supports failover for proxy reliability. Users can configure multiple proxies for a single rule, and SmartProxy will try each in sequence until one responds. If a configured proxy becomes unavailable during use, SmartProxy automatically falls back to the next proxy in the group without interrupting the user's browsing. This is particularly useful when working with rotating proxy lists or pools where individual proxies may go offline frequently, as the extension handles the fallback transparently without user intervention.

The pattern system is flexible. SmartProxy accepts patterns in several formats: exact domain names, wildcard patterns using * as a placeholder, regular expressions for complex matching, and simple domain suffix matching. A pattern example.com matches that exact domain. A pattern *.example.com matches any subdomain of example.com. A pattern ^https://api\\.example\\.com/.* matches only the api subdomain over HTTPS. This flexibility allows users to create precise rules that match exactly what they need to proxy and nothing more.

Request monitoring is built in. SmartProxy shows real-time information about requests, allowing users to see which requests are being proxied and which are not. A details view shows the current website, the current requests made by the page, and information about whether each request is proxified through a proxy or going direct. This transparency helps users debug rule mismatches or verify that their proxy configuration is working as intended. The monitoring view also functions as a way to quickly add new patterns, allowing users to right-click a request and immediately add a rule to proxy or not proxy similar requests in the future.

Adding proxies is straightforward. Users enter the proxy hostname, port, protocol (HTTP, HTTPS, or SOCKS5), and optional username and password if the proxy requires authentication. Multiple proxies can be saved and organized into groups. A group might contain several residential proxies for general browsing, another group might contain datacenter proxies for faster performance on certain tasks, and users can assign different groups to different pattern rules.

The browser interface is minimal and non-intrusive. SmartProxy adds an icon to the browser toolbar that shows the current status: whether proxying is enabled, which proxy is active, and access to the settings. Clicking the icon opens a popup menu showing configured proxies and quick-switch options. The full settings page provides detailed access to all rules, all proxies, and all configuration options.

SmartProxy's open-source model is a significant advantage for users concerned with privacy and transparency. The code is available for anyone to read, audit, or contribute to, reducing concerns about hidden behavior or tracking. Unlike closed-source proxy browser extensions that have sometimes been caught injecting ads, tracking browsing, or exposing credentials, SmartProxy's open development makes such misbehavior unlikely to go undetected.

The documentation is available on the GitHub repository, including a README explaining features, links to installation in each browser's extension store, and examples of common rule patterns. The extension's options page includes built-in help explaining each setting, making it practical to configure without consulting external documentation, though the GitHub page provides more detailed guidance for complex configurations.

Backup and restore functionality allows users to save and restore their entire configuration. This is useful for migrating settings to a new browser, sharing configurations with colleagues, or maintaining backups of complex rule sets. Settings can be exported as JSON files and imported into a fresh installation, making it straightforward to transfer configurations.

SmartProxy's limitations are primarily in scope. Like FoxyProxy, it controls only browser traffic, not system-wide application proxying. A desktop application will not be proxied by SmartProxy unless that application has independent proxy settings. SmartProxy also does not support advanced features like IP rotation (automatically changing to a different proxy every request) or traffic inspection and modification. It is a proxy router, not a proxy tester or a proxy debugger.

Protocol support includes HTTP, HTTPS, and SOCKS5, covering the most common proxy types. SOCKS4 and other older protocols are not supported, a limitation shared with most modern proxy clients due to declining use of older protocol versions.

Authentication is secure. Credentials are stored in the browser's local storage with encryption, not transmitted unencrypted or stored in cleartext. The extension supports proxy authentication (username and password) transparently for each request.

Compared to manually switching proxies, SmartProxy saves time and reduces errors. Compared to always-on VPN services, SmartProxy offers finer control and works with any proxy, including self-hosted proxies. Compared to using separate browser profiles for different proxy configurations, SmartProxy allows one browser window to handle all proxies simultaneously with automatic switching. Compared to paid proxy management extensions, SmartProxy is free and open-source, with no subscription and no dependency on a specific proxy provider.

SmartProxy is the choice for users who need proxy switching automation within a browser, value open-source software and transparency, and prefer to avoid paid subscription services. It works well for developers testing geolocation features, researchers working with multiple proxy scenarios, security professionals needing flexible proxy management, and anyone who finds themselves manually switching between proxied and direct connections frequently enough that automation would be valuable.