Add Thousands Separators
Format a plain numeric value with grouped integer digits without locale-dependent rounding or notation changes.
A QUICK WALKTHROUGH
How to use this tool
- Enter a number using digits, an optional leading sign, and an optional decimal fraction.
- Choose a thousands separator, or enter one custom separator character.
- Add the separator and copy the formatted result.
Strict numeric input
The tool accepts digits with an optional leading plus or minus sign and an optional decimal point followed by one or more digits. Whitespace, exponent notation, currency symbols, and already grouped values are rejected.
String-preserving formatting
Grouping is applied to the integer digits as text. The sign, leading zeroes, decimal point, and every fractional digit are preserved exactly; no locale formatting, rounding, or floating-point conversion is used.
Private local processing
Validation and formatting run entirely in your browser. Your number is not uploaded or stored by this page.
GOOD TO KNOW
Common questions
Are negative and positive signs preserved?
Yes. A leading minus or plus sign remains at the beginning of the result.
Are decimal digits preserved?
Yes. Only the integer part is grouped, and the decimal point and fractional digits stay exactly as entered.
Can I use my own separator?
Yes. Choose Custom and enter one separator character, such as an underscore or a space.
Does this use my browser locale?
No. It formats the input string directly, so locale settings do not change the result.