AppTools Regex Tester vs Debuggex

AppTools Regex Tester is a free browser-based tool for checking and debugging regular expressions. Its interactive sandbox updates matches as a pattern changes, with Global, Case-Insensitive, Multiline, DotAll, and Unicode flags. Listed regex flavors are JavaScript, PCRE (PHP), Python, and Go. A parser breaks tokens into human-readable explanations, including quantifiers and non-capturing groups, while a step-through debugger helps inspect pattern behavior. Full matches and capture groups are shown in different colors. The maker describes uses such as parsing logs, validating JSON payloads, cleaning datasets, creating input filters, writing scrapers, and transforming strings in CI/CD pipelines. The regex engine runs in the browser, and the maker says test strings are not transmitted over the network. The privacy policy says inputs stay in browser memory; minimal cookies and local storage retain interface preferences and language settings. AppTools also collects anonymous telemetry about tool popularity. The suite requires no sign-up, subscription, or installation and provides a global support contact. The Free plan is listed at free.

Debuggex is an online visual regex tester for JavaScript, Python, and PCRE. It offers visual and text modes, a step-through debugger, and pattern explanations for examining expressions. Users can add unit tests to check matches and subgroups as a regex changes, and browse a repository of pre-built expressions that includes tests. The service generates code snippets, saves patterns, and creates links that reopen expressions; expressions can also be embedded in StackOverflow answers. The Free plan costs nothing and includes two saved unit tests per regex and ten public expressions. Basic costs $5 a month, while Pro costs $15 a month. Enterprise has no listed price and includes options such as private server deployment, denial-of-service prevention, flexible user counts, an OEM license, and on-site training. The free tier excludes snippets based on expressions from the library. The privacy policy says saved or shared expressions can be viewed by anyone with the link, and previous versions are stored after updates. Debuggex is available on the web.