How to use the imei generator
- Select Generate or Validate from the mode dropdown.
- For generation, optionally enter an 8-digit TAC or leave it blank for a random one, then set the count and click Generate.
- For validation, paste a 15-digit IMEI into the input field and click Generate.
- Review the output list or the breakdown showing the TAC, serial number, and check digit.
How the IMEI structure works
An IMEI (International Mobile Equipment Identity) is always exactly 15 digits long. The first 8 digits form the Type Allocation Code (TAC), which identifies the device model and manufacturer. The next 6 digits are the serial number assigned by the manufacturer. The final digit is a check digit calculated using the Luhn algorithm to catch transcription errors.
When you use this IMEI generator, it builds the first 14 digits (either from your supplied TAC plus random serial digits, or fully random) and then computes the 15th digit so the entire number passes the Luhn check. This produces a structurally valid but completely fake IMEI suitable only for software testing.
Calculating the Luhn check digit
The Luhn algorithm processes the first 14 digits from right to left. Every second digit (starting from the rightmost of the 14) is doubled. If doubling produces a number greater than 9, subtract 9. Sum all the resulting digits together with the untouched digits. The check digit is the amount needed to reach the next multiple of 10.
For example, take the partial IMEI 49015420323751. Doubling every second digit from the right gives: 4, 18, 0, 2, 5, 8, 2, 0, 3, 4, 3, 14, 5, 2. After reducing values over 9 (18 becomes 9, 14 becomes 5): 4+9+0+2+5+8+2+0+3+4+3+5+5+2 = 52. The next multiple of 10 is 60, so the check digit is 60 minus 52, which equals 8. The full IMEI is 490154203237518.
Choosing a TAC for testing
The TAC is the first 8 digits and is allocated by the GSMA to a device model. This tool does not map TACs to brands, because that data is maintained in the GSMA database and we do not republish unverified lists. If your software needs a specific model, take the TAC from your own test devices (it is the first 8 digits of their IMEI, shown by dialing *#06#) and enter it in the TAC field. The value 49015420 is the widely quoted example TAC used in the Luhn worked example above.
Legal note: changing the IMEI of a real device is illegal in many countries. These generated numbers are for testing software, such as form validation and databases, and must not be programmed into a phone.
Why developers need fake IMEI numbers
Mobile applications, device management platforms, and telecom APIs often require an IMEI field during registration or hardware tracking. When building automated test suites, hardcoding real device identifiers creates privacy risks and can trigger fraud detection systems. A fake IMEI generated locally avoids both problems.
This tool pairs well with other test data utilities. For instance, you might use the MAC address generator for network interface testing, the VIN generator for automotive software, or the credit card generator for payment flow validation. All produce structurally valid but non-functional identifiers.
Validation mode and error handling
Switching to validate mode lets you act as an IMEI checksum verifier. Paste any 15-digit string and the tool will confirm whether it passes the Luhn check. If it does, the output breaks down the TAC, the 6-digit serial number, and the check digit separately.
The validator rejects input that contains letters, spaces, or symbols. It also rejects strings that are shorter or longer than 15 characters. This strictness mirrors how production systems should handle incoming IMEI data before storing it in a database or passing it to a carrier API.
Worked examples
| Example | Input | Result |
|---|---|---|
| Five random IMEIs | Mode: generate; Count: 5 | 308474041635828, 654544206724557, 744557056742224, 027882604217026, 593463368927979 |
| Three IMEIs with custom TAC | Mode: generate; Count: 3; TAC (optional): 49015420 | 490154209963984, 490154207412752, 490154207165038 |
| Validate a known good IMEI | Mode: validate; Count: 1; IMEI to validate: 490154203237518 | Status: Valid; TAC: 49015420; Serial: 323751; Check digit: 8 |
FAQ
Are the generated IMEIs real device identifiers?
No. This IMEI generator produces fake IMEI numbers strictly for software testing and development. They have the correct mathematical structure but are not registered to any physical device.
What is the Luhn algorithm used for in an IMEI?
The Luhn algorithm calculates the 15th check digit from the first 14 digits. It detects single-digit typos and most adjacent-digit transpositions when someone manually types an IMEI number.
Can I specify my own TAC prefix?
Yes. Enter any 8-digit number in the TAC field. The generator will append 6 random serial digits and compute the correct check digit. Leave the field blank to generate a fully random 14-digit base.
Why does validation reject my input?
A valid IMEI must be exactly 15 numeric digits with no spaces or letters, and it must pass the Luhn checksum. If any of these conditions fail, the tool returns an error.
Is my data sent to a server?
No. Everything runs locally in your browser. No IMEI numbers you generate or validate are transmitted anywhere.
How many IMEIs can I generate at once?
You can generate between 1 and 20 IMEIs per request using the count field. Counts outside 1 to 20, or that are not whole numbers, return an error instead of being adjusted.
Is it legal to change a phone's IMEI?
In many countries it is illegal to change the IMEI of a device. This tool produces numbers for testing software only and is not meant for reprogramming hardware.