AppTools Regex Tester vs regex101

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.

regex101 is an online workspace for building, testing and debugging regular expressions. Its editor supports PCRE2, JavaScript, Python, Golang, Java,.NET 10.0, Rust, POSIX ERE, POSIX BRE and legacy PCRE. Explanations show how parts of a pattern match according to the selected flavor, and a step-through debugger helps follow matching. Match results can be exported as JSON, JSON Lines, CSV or plain text. Developer options include HTTP APIs, an MCP server, editor links and a separately licensed parser package. The workspace API stores editor data but does not provide a remote matching endpoint. File loaders read text, bytes and supported documents locally in the browser; saving or sharing workspace input can send it to the workspace service. Free includes core tools, one test string and saved workspaces with an account. Pro costs €4.99 a month, billed yearly, and adds multiple test strings, substitution pipelines, advanced benchmarking, formatting and an ad-free workspace. Enterprise is a self-hosted option with documented deployment on Linux using Docker Compose, MySQL and Redis.