Email Validator: Check Address Syntax and Understand the Limits
Check single or bulk email syntax with FindUtils. Learn what passes, what needs a separate DNS check, and why syntax cannot prove mailbox ownership.
Enter Phone Number
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Try These Examples
How to Validate a Phone Number
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Select the Country
Choose the country from the dropdown menu. The validator uses country-specific dialing rules, prefix patterns, and number length requirements to check each number accurately. -
Enter the Phone Number
Type the phone number in the input field. You can enter it with or without the country code, with spaces, dashes, or parentheses. The tool strips formatting characters automatically. -
Review the Validation Result
The tool instantly shows whether the number is valid, invalid, or possibly valid. It also detects the phone type such as mobile, fixed line, VoIP, or toll-free. -
Copy the Formatted Output
Choose from E.164, international, national, or Tel URI format. E.164 is the standard for APIs and databases, while the national format is best for local display.
Guides and articles
Read instructions and examples for this tool.
E.164 Phone Number Validator: Format and Numbering Limits
Check an international phone number with FindUtils. Learn E.164 notation, country codes, length limits, and why valid format does not prove reachability.
Common Use Cases
Form Input Validation
Verify phone numbers entered in signup forms, checkout pages, and contact forms before storing them. Reject invalid formats early to prevent delivery failures for SMS notifications and two-factor authentication codes.
Database Cleanup and Normalization
Convert a messy database of phone numbers into a single consistent format. Standardize everything to E.164 so your records are searchable, deduplicated, and compatible with messaging APIs like Twilio and Vonage.
International SMS and Voice Campaigns
Before sending bulk SMS or making automated calls, validate each number against country-specific rules. Identify phone types to route mobile numbers to SMS channels and fixed lines to voice channels.
CRM Data Quality Auditing
Audit customer records for invalid or incorrectly formatted phone numbers. Detect the country of origin, normalize formatting, and flag numbers that cannot receive SMS for better campaign targeting.
Why use Phone Number Validator?
Ensure phone numbers are valid before storing in databases or sending SMS. This tool validates numbers against country-specific rules, detects the phone type (mobile, fixed line, etc.), and provides multiple formatting options including the E.164 standard used by most APIs.
Phone Number Validator is a browser-based tool that checks whether a phone number is valid for a given country and converts it into standardized formats. It uses the same libphonenumber library that powers phone validation in Google products, applying country-specific rules for number length, prefix patterns, and regional formatting. No data leaves your browser during validation.
The tool supports over 200 countries and territories, detecting the phone type (mobile, fixed line, VoIP, toll-free, premium rate) and outputting numbers in E.164, international, national, and Tel URI formats. E.164 is the format required by most telephony APIs including Twilio, AWS SNS, and Vonage. Developers building signup flows can pair this tool with the Email Validator to verify both contact fields, or use the Regex Tester to build custom validation patterns for specific number formats.
For teams handling international customer data, consistent phone formatting prevents duplicate records and failed message deliveries. Use this tool alongside the Data Sanitizer to clean bulk datasets, or check domain-level contact info with the DNS Lookup tool. All processing happens client-side with no server uploads, making it safe for sensitive contact information.
How it compares
Online phone validators fall into two categories: format validators that check structure and carrier lookup services that verify whether a number is active. This tool is a format validator, using Google's libphonenumber to check against official numbering plans for each country. It is available with no API key, no rate limits, and no data uploaded to a server. Paid carrier lookup services like NumVerify and Abstract API charge per request and require account signup, but they can confirm whether a number is currently active and identify the carrier.
Compared to other validators, most web-based alternatives send your input to their servers for processing. This tool runs entirely in the browser, so phone numbers never leave your device. For developers who need programmatic validation, the same libphonenumber library is available as an npm package, but this tool provides instant results without any setup.
Tips for Phone Number Validation
- Always store phone numbers in E.164 format (+[country code][number]) for maximum compatibility with APIs and global databases.
- Include the country code when validating numbers from international users to avoid ambiguous results with similar national formats.
- Use the phone type detection to route messages correctly. Send SMS only to mobile numbers and use voice calls for fixed-line numbers.
- Validation checks format rules, not whether a number is currently in service. Combine with a live carrier lookup for deliverability checks.
- Strip all formatting characters like spaces, dashes, and parentheses before storing numbers. The E.164 output does this automatically.
Frequently Asked Questions
What is E.164 format?
E.164 is the international standard for phone numbers. It includes the country code with a + prefix, followed by the national number without any formatting. Example: +14155552671. Most APIs and databases prefer this format.
How accurate is the validation?
The validator checks number length, prefix validity, and format rules for each country. It can determine if a number is valid for a specific country, but cannot verify if the number is actually in service or assigned.
What phone types can be detected?
The tool can identify: Mobile, Fixed Line, toll-free, Premium Rate, VoIP, Pager, and more. Detection is based on number prefixes and ranges defined for each country.
Can I validate numbers without the country code?
Yes, select the country from the dropdown and enter just the national number. The validator will automatically apply the correct country code for validation and formatting.
Does this phone validator require a signup?
No. It is available with no usage limits, no signup, and no API key required. The tool runs entirely in your browser using the libphonenumber library.
Is it safe to enter phone numbers in this tool?
All validation happens locally in your browser. Phone numbers are never sent to any server, making it safe for personal and business numbers. No data is stored or logged.
What is the difference between E.164 and international format?
E.164 is a compact format with no spaces or dashes (e.g., +14155552671). International format includes spaces or dashes for readability (e.g., +1 415-555-2671). Use E.164 for databases and APIs, and international format for display.
How many countries does the validator support?
The tool supports over 200 countries and territories worldwide. It uses Google's libphonenumber database, which is continuously updated with the latest numbering plan changes from telecom regulators.
Can I validate landline and toll-free numbers?
Yes. The tool validates all phone types including fixed lines, toll-free numbers, premium rate numbers, VoIP numbers, and shared-cost numbers. It also identifies the type after validation.
What does 'Possibly Valid' mean?
A 'Possibly Valid' result means the number has a correct format and length for the selected country, but falls in a range that may not have been assigned yet by the telecom regulator. The number could still work.