Validate and explain a regular expression (JavaScript flavour)
Validate and explain a regular expression (JavaScript flavour): is it valid, what each part means in plain English, whether it risks catastrophic backtracking (ReDoS), and what it matches in up to 20 test strings (with groups). POST {pattern, flags, tests}.
Answeringour last check, 2026-09-28
1 of 1checks answered this week
17 msmedian answer time
$0.001listed price per call
$0.001price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
POST https://aayatai.com/regex/explain
| Category | Code and developer |
|---|---|
| Provider host | aayatai.com |
| Networks | eip155:137, eip155:42161, eip155:8453, solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp |
| Payment schemes | exact |
| Self-reported calls, 30 days | 1 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-09-28 | valid payment request | 402 | $0.001 | 17 ms |
Example input (from the provider)
{
"body": {
"flags": "",
"pattern": "^(\\d{3})-(\\d{4})$",
"tests": [
"555-1234",
"5551234"
]
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"properties": {
"flags": {
"description": "JavaScript flags: g i m s u y d v.",
"maxLength": 8,
"type": "string"
},
"pattern": {
"description": "The regex source, without slashes, e.g. ^(\\d{3})-(\\d{4})$",
"maxLength": 500,
"minLength": 1,
"type": "string"
},
"tests": {
"description": "Strings to try it on.",
"items": {
"maxLength": 500,
"type": "string"
},
"maxItems": 20,
"type": "array"
}
},
"required": [
"pattern"
],
"type": "object"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"error": {
"description": "The syntax error if invalid.",
"type": [
"string",
"null"
]
},
"flags": {
"type": "string"
},
"groups": {
"description": "Number of capturing groups.",
"type": "integer"
},
"parts": {
"items": {
"type": "object"
},
"type": "array"
},
"pattern": {
"type": "string"
},
"risk": {
"description": "Why it may backtrack catastrophically, or null. Tests are not run when set.",
"type": [
"string",
"null"
]
},
"tests": {
"items": {
"type": "object"
},
"type": "array"
},
"valid": {
"type": "boolean"
}
},
"required": [
"valid",
"error",
"parts",
"risk",
"tests"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}