Check phone number format validity across a CSV column

Validating phone numbers before sending SMS or making API calls to Twilio, Africa's Talking, or Vonage prevents failed deliveries and wasted message credits. The E.164 international standard (ITU-T E.164) defines valid number length (7–15 digits) and country code prefixes. DataFix checks digit count, detects missing + prefix, flags numbers with too few or too many digits, and applies country-specific rules (e.g., Kenya's Safaricom numbers must be 12 digits in E.164 form: +254 followed by 9 digits). Phone numbers collected from web forms and international checkout funnels frequently arrive in inconsistent, non-standard formats containing national dialing prefixes, dashes, parentheses, extensions, and country codes. Non-standard phone records cause SMS delivery failures, CRM sync errors, and broken telephony integrations. DataFix validates telephone numbers against international E.164 and ITU standards, checking digit lengths, valid country prefixes, and formatting anomalies across national numbering plans while maintaining total data privacy. Inconsistent telephone records containing regional dialing prefixes, missing country codes, or alphabetic extensions disrupt automated SMS notifications and CRM synchronization. Validating telephone digits against ITU-T E.164 standards ensures that international numbers conform to standardized digital telecommunications formats.

How does phone number validation work?

DataFix strips non-digit formatting characters, verifies whether the digit length matches international ITU-T E.164 specifications (7 to 15 digits), and checks country-specific numbering plan constraints such as Kenyan Safaricom (+254 7xx or +254 1xx) lengths.

Does this tool detect whether a mobile line is active and reachable?

No. DataFix runs syntactic and format validation locally in your browser. It does not perform active HLR (Home Location Register) ping lookups or network carrier queries, keeping your contact database strictly private.

Can it validate local Kenyan phone formats like 0722 112 233?

Yes. It recognizes national 10-digit Kenyan numbers starting with 07 or 01, validates that they have exactly 10 digits, and notes that converting them to +254 E.164 format is recommended before SMS gateway submission.

Are my phone numbers uploaded to external servers?

Never. All data parsing, regex matching, and validation logic run entirely client-side in your web browser. No customer contact data is ever transmitted over the network.

Validate

Validate CSV

Audit CSV files for structural errors, encoding problems, and row-length inconsistencies.

Open Tool →

Validate

Validate JSON

Parse and validate JSON strings to expose syntax errors at exact line and column positions.

Open Tool →

Validate

Find Duplicate Rows

Identify and count duplicate rows in CSV files by exact match or by key column selection.

Open Tool →