Phone Formatter

Format phone numbers to E.164 or national format. Auto-detect country codes. Free, private — all in your browser.

About Phone Formatter

Standardize phone numbers from anywhere in the world. Whether you need E.164 format for APIs, national format for local display, or just want to detect which countries your numbers belong to — this tool handles it all instantly and privately.

E.164 Format

Convert any phone number to the international E.164 standard (+1234567890) — the format required by Twilio, SMS APIs, and most telecom services.

National Format

Format numbers in local style with proper area codes and grouping for readability. Great for display in customer-facing applications.

Country Detection

Auto-detect country codes from the international prefix. See which country each number belongs to with a detailed breakdown.

Private & Secure

Phone numbers processed locally in your browser. No uploads, no servers. Your contact data stays on your device.

📋 Common Use Cases

Email List Cleaning

Validate email addresses before sending campaigns. Remove invalid addresses, catch typos in domain names, and improve deliverability rates.

Phone Number Standardization

Normalize phone numbers from international customers into a consistent format. Ensure your CRM, dialer, or messaging system accepts every number.

Form Data Quality

Validate user-submitted data before storing it in your database. Catch errors at entry time rather than discovering them during analysis.

Database Migration Prep

Clean and validate data before importing into a new system. Find and fix format issues that would cause import failures.

🪜 How to Use This Tool

  1. Paste or upload your data
    Enter individual values or upload a file with multiple records. Most validators accept CSV, TSV, and plain text.
  2. Configure validation rules
    Set the level of validation, choose output format, or specify which checks to perform — syntax only, domain verification, or full deliverability.
  3. Review validation results
    See a summary of valid/invalid counts and per-record details. Invalid entries are flagged with the specific reason for failure.
  4. Export cleaned data
    Download validated records or fix issues directly. Separate valid and invalid entries for targeted cleanup.

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Frequently Asked Questions

Is this data tool free?▼
Yes. All data tools are completely free. No signup needed.
Is my data sent to a server?▼
No. All data processing happens in your browser. Your JSON, CSV, SQL, and text data never leaves your device.
Can these handle large files?▼
JSON formatter and CSV tools comfortably handle files up to ~10MB in browser. Performance depends on your device for larger datasets.