Example strings
Each line becomes a sample input for pattern generation.
Email pattern
High confidence/^[^\s@]+@[^\s@]+\.[^\s@]+$/iMatch standard email-style addresses.
Smart Regex Builder
Regex for Date Validation
Generate and test regex for dates — ISO YYYY-MM-DD, DD/MM/YYYY, MM-DD-YYYY, and other formats — in a browser-based regex builder.
- Generate from examples
- Test with live match highlights
- Copy for JS, TS, or Python
Quick modeAutosaves in this browser
Quick templates
Generated pattern
Use the generated regex as-is, or move it into test mode to tweak flags and cases.
/^[^\s@]+@[^\s@]+\.[^\s@]+$/igimsu
Live results
Generate, explain, and validate the pattern in one pass.
See the regex, what it means, and which test lines pass without digging through token noise.
Active regex
/^[^\s@]+@[^\s@]+\.[^\s@]+$/i3 lines • 3 matched • 0 unmatched
Pattern summary
Email pattern • High confidence
Match standard email-style addresses.
const regex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/i;
Match results
One row per test string
Case 1
Matchedalex@example.com✔ Full line matched.
Case 2
Matchedmaya@company.io✔ Full line matched.
Case 3
Matchedtest.user@site.dev✔ Full line matched.
What this regex matches
- Matches the full line from start to end.
- Requires text before and after @.
- Ignores letter case.
- Matches all 3 current test lines.
Show detailed breakdown
^Start of string
Match from the start of the string.
[^\s@]+One or more character outside sets
Match one or more character outside sets.
@@ symbol
Match the @ character.
[^\s@]+One or more character outside sets
Match one or more character outside sets.
\.Literal .
Match the literal character ..
[^\s@]+One or more character outside sets
Match one or more character outside sets.
$End of string
Match up to the end of the string.
Why it helps
Why generate date regex with a builder
Match the exact date formats your forms, logs, or filenames use instead of a generic pattern.
Test valid and invalid samples like 2026-13-40 so impossible month or day values fail.
Read a plain-English explanation so the format rule stays easy to maintain.
How to use it
How to build a date validation regex
1 Paste dates that should match in the format you expect, like 2026-07-17 or 17/07/2026.
2 Add wrong-format and impossible-value samples that should fail.
3 Review the generated pattern and explanation, then copy it into your validation code.
Quick tips
Date regex tips
For ISO dates, ^\d{4}-(0[1-9]|1[0-2])-(0[1-9]|[12]\d|3[01])$ checks the shape and blocks impossible months and days.
Regex can't fully validate calendar rules like leap years — parse the value with a date library after the format check.
Anchor date patterns with ^ and $ so partial matches inside longer strings don't slip through.
FAQ
Date regex questions
Can this generate regex for YYYY-MM-DD dates?
Yes. Provide ISO date samples and the builder generates a pattern you can test against valid and invalid values before copying it.
Can regex validate leap years?
Not practically. Use regex to check the format shape, then let a date parser confirm the value is a real calendar date.
Can I match DD/MM/YYYY and MM/DD/YYYY?
Yes, but the two are indistinguishable for days 1–12, so pick one convention per input source and validate against it explicitly.
Can I extract dates from log lines?
Yes. Drop the anchors and test the pattern against full log lines so it captures dates wherever they appear.
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