I Built a Regex Tester Because Regex101 Sends Your Data to a Server

Last week I was debugging a CloudFront log parser and pasted a chunk of raw access logs into Regex101. Mid-keystroke, I realized those logs contained client IPs, user agents, and request paths from production. All of it, shipped off to someone else’s server for “processing.” That’s the moment I decided to build my own regex tester. The Problem with Existing Regex Testers I looked at three tools I’ve used for years: Regex101 is the gold standard. Pattern explanations, debugger, community library — it’s feature-rich. But it sends every keystroke to their backend. Their privacy policy says they store patterns and test strings. If you’re testing regex against production data, config files, or anything containing tokens and IPs, that’s a problem. RegExr has a solid educational angle with the animated railroad diagrams. But the interface feels like 2015, and there’s no way to test multiple strings against the same pattern without copy-pasting repeatedly. Various Chrome extensions promise off