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Pattern (JavaScript RegExp)
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Engine is browser JavaScript (similar to regexr-style checks). Java, Python re, C#, and SQL flavors differ — use this to prototype, then adapt syntax.
Sample presets
Test string
Matches
Hello
regex
101
test
JS
Python
re
and
SQL
style
validation
here
Regex Tester & Visualizer helps you complete this task in seconds directly in the browser without installing extra software.
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Results are generated from your current inputs and tool logic. For AI actions, output depends on model response quality and prompt context.
No. This page uses the browser JavaScript RegExp engine. Syntax is often close, but Java, Python re, C#, SQL Server, and Google Sheets regex all have differences—use this tool to prototype, then port carefully.
Use the match list to confirm your pattern first. For replace, mentally substitute each match with your replacement string, or run a quick snippet in your target language.
Modern browsers support some lookbehind features, but engines vary. If a pattern fails unexpectedly, confirm support in your deployment targets.