Felo

UTF-8 Byte Counter Online

Count the UTF-8 bytes in any text and get the exact total plus a per-character cost breakdown. Unlike a bare counter, it also reports character, code-point, and line counts and can batch several strings at once. Try it online.

What is UTF-8 Byte Counter Online?

UTF-8 Byte Counter Online is a conversational tool that tells you exactly how many bytes a piece of text occupies when encoded as UTF-8. You paste or type your text, and the agent returns the byte total, a breakdown of how many bytes each character costs, and supporting counts such as characters, code points, and lines. It is built for the everyday job of checking whether a string fits a byte limit in a database column, an API field, an HTTP header, or a message payload.

Key Features

Exact UTF-8 byte total. ASCII letters cost 1 byte, accented Latin characters typically cost 2, most CJK characters cost 3, and emoji cost 4. The agent applies the standard UTF-8 ranges and reports the sum.
Per-character cost breakdown. See which characters are driving the total, so a long string of emoji is immediately visible as the reason a limit is exceeded.
Supporting counts. Character count, code-point count, and line count are reported alongside the byte total.
Batch counting. Paste several strings separated by a marker and get a byte total for each one.
Budget check. Give a byte limit and the agent reports how much room remains or how far over you are.

How to Use

Paste or type your text into the chat. If you have several strings, separate them with a clear marker such as | and say you want each counted separately; the separator should not appear inside the strings themselves.
Optionally state a byte limit, for example "limit is 255 bytes," so the agent can report the remaining headroom.
Read the byte total in the copyable result block, then ask for a breakdown or a re-count after you edit the text.

Example Use Cases

Checking a database column limit. You have a product description with accented characters and want to know its UTF-8 byte count before inserting it into a VARCHAR(255) column.
Counting emoji in a message payload. A notification template contains emoji, and you need the byte count to confirm it fits a payload budget.
Batch counting API field values. You paste ten short strings and ask for the UTF-8 byte count of each so you can flag the ones over a limit.

A quick before-and-after example: the text café has 4 characters but 5 UTF-8 bytes, because é costs 2 bytes. The text hi 😀 has 4 characters but 7 bytes, because the emoji costs 4.

Tips for Best Results

Paste the exact text, including trailing spaces and newlines, since those count toward the total.
If you are checking a limit, state the limit in bytes, not characters, so the comparison is meaningful.
For batch work, use a separator that does not appear in your strings.

FAQ

What input format does it accept?
Plain text of any length you can paste into the chat. There is no file upload; paste the content directly. The agent returns the exact byte total for any pasted text; if the input is too large to process, it says so explicitly rather than summarizing.

How accurate is the byte count?
The count follows the standard UTF-8 encoding ranges and is computed deterministically, so ASCII, accented characters, CJK text, and emoji are all counted correctly. Lone or unpaired surrogate characters are flagged, and the total is reported with the stated assumption (standard replacement behavior).

How does this compare with some free text tools?
This agent returns the byte total and also explains which characters cost 2, 3, or 4 bytes, reports character and code-point counts, and can count several strings in one request. It does not store your text or offer accounts.

Does it translate or change my text?
No. It only measures. Your text is preserved exactly in the result block.