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Validator Tool

Validate common strings right in your browser. Choose a type, paste one value or a list (one per line), and get clear VALID/INVALID results with short reasons.

No uploads, no network calls—everything runs locally.

Category: General · URL: /tools/validator-tool.html
Options
For most types, validation runs line-by-line. For JSON, the full textbox is validated as one JSON value.

  


  


          

          

            Privacy: runs locally in your browser. No uploads, no tracking scripts.
          

        

      


      
    


    

      
How to use

      
Select what you want to validate, paste your values, then run validation.
  1. Pick a Validation type (Email, URL, IPv4, JSON, etc.).
  2. Paste input (for most types: one item per line; for JSON: paste the full JSON).
  3. Adjust options like Trim whitespace or Ignore empty lines.
  4. Click Validate to see a summary and per-line results.

      

        Keywords this page targets (natural cluster): validator tool, online validator tool, validate email address, email validator online, url validator, validate url format, ip address validator, ipv4 validator, ipv6 validator, domain name validator, json validator, uuid validator, base64 validator, phone number validator, e164 validator, hex color validator, iso date validator, credit card validator luhn, iban validator, bulk validator list, validate multiple lines, string format validator
      

      

        Secondary intents covered: Check if a pasted list contains invalid entries, Quickly validate user input before saving or importing, Validate a URL with or without requiring http(s)://, Verify a JSON snippet is parseable and get the parse error location, Validate payment-like strings (credit card via Luhn, IBAN via mod-97), Validate technical identifiers (UUID) and network values (IP addresses), Copy validation results for tickets, logs, or spreadsheets, Spot formatting issues caused by whitespace or empty lines
      

    


    

      
FAQ

    
Does this validator tool send my data to a server?
No. Validation runs in your browser and the tool does not make network requests.
Can I validate multiple values at once?
Yes—paste one item per line (most types) and the output will show a VALID/INVALID line for each.
Why does JSON validation ignore “one per line” behavior?
JSON is validated as one complete value, so the entire textbox is parsed as a single JSON document.
Is the email/URL validation fully RFC compliant?
No. It uses practical checks that catch common mistakes, but it’s not a full RFC parser.
What does “credit card (Luhn)” mean?
It checks the number using the Luhn checksum; it doesn’t confirm the card exists or is usable.
What does the IBAN check validate?
It verifies the general IBAN structure and mod-97 checksum; it may not enforce every country’s exact length rules.
How can I avoid false negatives caused by spaces or blank lines?
Enable Trim whitespace and Ignore empty lines in the Options area.