E164.tools

Normalize Messy Phone Numbers for CRM & API Imports

Upload a CSV, normalize the phone column into E.164, keep the rest of each row intact, and separate risky rows before import.

Browser-based No signup Files stay on your device

Upload your CSV file

Drag and drop a CSV export here, or click to browse from your computer.

The tool will clean the phone column, keep safe rows import-ready, and separate risky rows into a needs-review file.

Accepts .csv files up to 50 MB

Processed locally in your browser. No server upload. No CSV retention. On slower devices, very large files may take longer to process or make the page temporarily unresponsive.

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1

Upload CSV

Drag and drop your file. Data stays local in your browser.

2

Select Columns

Choose which column holds phone numbers and optionally a country column.

3

Process

The tool cleans formats, validates structure, and applies E.164 rules.

4

Download

Get separate cleaned and needs-review files ready for CRM import.

View detailed guide

Why Formatting Matters

Prevent Failed Imports

Salesforce, HubSpot, and communication tools frequently reject CSV imports with invalid phone structures.

Fix Broken Dialers

Tools like Aircall and RingCentral require E.164 (+15551234567) to successfully route international calls.

Catch Ambiguous Rows

Isolate rows with extensions (x123) or multiple numbers before they corrupt your database.

Standardize Storage

Ensure every phone record in your system follows a single, predictable standard.

What is E.164 Format?

E.164 is the international standard for telephone numbers — a plus sign, country code, and subscriber number, with no spaces or formatting characters.

Input E.164 Result
(415) 555-2671 +14155552671
020 7183 8750 +442071838750
Learn more about E.164

Sample Data

Not ready to use your own data? Download our sample CSV with varied formats, international codes, and tricky inputs.

name phone
John Doe(555) 123-4567
Jane Smith07700 900077
Messy Data800-555-0199 x123
View sample outputs

Frequently Asked Questions

Does my file leave my computer?

No. All processing happens entirely within your web browser using JavaScript. We do not upload your CSV file or its contents to any server.

What does "Needs Review" mean?

Rows are flagged when the cell contains extensions (x123), text notes, or multiple numbers. Download them separately to clean manually.

What if my CSV has numbers from many countries?

Select a country column during configuration. The tool will parse each row using its specific country code.

How do I handle local numbers without country codes?

You can optionally provide a default country during setup for local-format numbers. If your CSV contains mixed-country data, leaving it blank is safer so ambiguous rows can be reviewed instead of guessed.

View all FAQs
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