Static + Browser-Only

JSON Regex Tester and Extractor Online

Test regex rules against JSON online. Put regex rules JSON on the left, validate a JSON payload on the right, and highlight invalid or missing fields directly in the browser.

This is useful for API payload review, fixture validation, nested field checks, and JSON regex extraction workflows without uploading data.

Rules

Regex rules JSON

Paste regex rules JSON on the left and a JSON payload on the right.

Payload

Payload JSON

Validated payload with field-level regex highlights will appear here

What Is It

What is a JSON regex tester and extractor?

This page validates JSON against a rules JSON object where each field contains a regex pattern. It helps teams test whether nested JSON fields match expected formats before sharing, debugging, or using that payload elsewhere.

Use Cases

When should you validate JSON with regex rules?

Check API fixtures before QA or release review
Validate form payload patterns like email, phone, and member IDs
Review nested objects and field formats against internal standards
Highlight JSON fields that break expected regex rules

Features

What this JSON regex validation tool can do

Use a JSON object of regex rules as the source of truth
Validate nested fields such as customer.memberId and customer.email
Highlight invalid and missing fields in JSON payloads
Run locally in the browser with no upload

FAQ

Common questions

How do I test a payload against regex rules?

Paste your regex rules JSON on the left, paste the matching payload format on the right, and run validation. Invalid or missing fields are highlighted in red inside the payload viewer.

Can I validate nested JSON fields?

Yes. Nested objects are supported, so rules like customer.memberId and customer.email work when the JSON structure matches.

Does this work only for JSON?

Yes. This page is focused on JSON validation. Other regex pages are available for XML, HTML, CSV / TSV, SQL, logs, plain text, and HTTP payloads.

Does this upload the rules or payload?

No. Validation runs locally in the browser and no rules JSON or payload content is uploaded during the workflow.

Why JSON regex validation matters before sharing or testing payloads

Teams often assume sample payloads are valid until a downstream system rejects them. A JSON regex tester makes those formatting problems visible before a payload reaches QA, support, docs, vendors, or AI workflows.

This is useful for JSON fields such as emails, phone numbers, IDs, event keys, nested member IDs, and status values where format errors are easy to miss.

Teams often search for a free regex tester online when they need to validate field formats, check sample payloads, enforce naming rules, or catch invalid values before QA, release review, or external sharing. A browser-only regex validator is especially useful when payloads, logs, or request examples should stay local and should not be uploaded to a remote validator.

Examples

Example JSON rules and payload

The rules JSON defines regex patterns, and the payload is a JSON object with invalid fields highlighted.

Regex rules JSONValidation rules

{
  "email": "^[A-Z0-9._%+-]+@[A-Z0-9.-]+\\.[A-Z]{2,}$",
  "phone": "^\\d{3}-\\d{3}-\\d{4}$",
  "status": "^(active|pending|paused)$",
  "customer": {
    "memberId": "^mem_\\d{3,}$"
  }
}

Payload JSONInvalid fields highlighted

{
  "email": "john@example.com",
  "phone": "2045550199",
  "status": "trial",
  "customer": {
    "memberId": "204"
  }
}