Result
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Facts and limits of this method
| Default mode | Replaces every period, including sentence-ending ones |
|---|---|
| "Digits only" mode | Converts a period only when it sits directly between two digits |
| Typical use | Preparing US-formatted decimal numbers (3.14) for European-locale software (3,14) |
| Version numbers | In digits-only mode, "1.2.3" becomes "1,2,3" — treated the same as a decimal number |
| Non-numeric periods (URLs, files) | Untouched in digits-only mode, since letters aren't digits |
| Counter | Reflects the number of replacements actually made under the selected mode |
When it misleads you
- With the default settings (digits only off), every period in the text becomes a comma — including ones that end sentences and abbreviations. Running this on prose replaces sentence-ending periods too, which is rarely what you want; turn on "digits only" when you're formatting numbers, not punctuation.
- With digits only on, a period converts only when it sits directly between two digits, so it won't touch the period at the end of "It costs 3.14." (that last period follows a digit but is not followed by one). But it will convert every digit-period-digit sequence it finds, including ones in version numbers like "1.2.3", turning them into "1,2,3" even though those aren't decimal numbers.
- A period followed by a non-digit, as in a domain name ("site.com") or a file extension ("report.pdf"), is never touched by digits-only mode, since a letter can't stand in for a digit — but a period directly between two digits ("Chapter.5" if written that way) could be mistaken for a decimal separator and converted even when it isn't one.
- A number using periods as thousands separators in some European conventions (e.g. "1.234.567") would have every digit-period-digit pair converted, producing "1,234,567" — the reverse of what's intended, since in that convention those periods are thousands separators, not decimal points.
How it is calculated
In the default mode, the tool matches every literal period in the text and replaces it with a comma, counting every occurrence.
In digits-only mode, it looks specifically for a digit, followed by a period, followed by another digit, and replaces only the period in that pattern — counting only these matches.
Everything else in the text — letters, other punctuation, spaces — is left exactly as it was.
The counter shown always reflects how many replacements were actually made under whichever mode is selected.
Questions and answers
What's the point of "digits only" mode?
It lets you convert decimal numbers to the European comma format without touching sentence-ending periods or abbreviations elsewhere in the text.
Will it break version numbers like 1.2.3?
Yes, if digits-only mode is on — each period between two digits matches the same pattern as a decimal point, so "1.2.3" becomes "1,2,3".
How is this different from the comma-to-dot converter?
That tool does the opposite conversion — it turns commas into periods, for going from European decimal formatting back to a dot.
Does it touch periods in domain names or filenames?
Not in digits-only mode, since the character after the period usually isn't a digit. In the default mode (digits-only off), every period is replaced regardless of context.
Is my text sent anywhere?
No. Everything runs in your browser; the text is never transmitted.