ToolWren › Byte Counter

UTF-8 Byte Counter

Count the UTF-8 byte size of any string, along with its character count and UTF-16 code units.

100% client-side · nothing is uploaded

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How to use the Byte Counter

Type or paste your text into the Input box.
The converted result appears automatically in the output area — no button to press.
Review the output, then click Copy to copy it to your clipboard.
Edit the input at any time and the result updates live.

Privacy: this tool runs entirely in your browser. Your input is never sent to, received by, or stored on any server — there are no uploads and no tracking of what you enter.

About Byte Counter

Bytes vs characters

A character isn't always one byte. In UTF-8, ASCII is 1 byte but accented letters take 2 and emoji take 4, so byte size differs from character count.

Why it matters

Database column limits, SMS segments, API payload sizes and tweet limits are often measured in bytes or code units, not characters.

What you see

Character count, UTF-8 byte count and UTF-16 code-unit count for the same text.

Frequently asked questions

Why is byte count higher than characters?

Non-ASCII characters use multiple UTF-8 bytes each.

How many bytes is an emoji?

Most emoji are 4 bytes in UTF-8.

What are UTF-16 code units?

How JavaScript and some databases count string length internally.