Prompt Character Counter
Check the size of a prompt or any text against a limit. The counter shows characters as people see them (emoji and accented letters count once), characters without spaces, words, sentences, lines, paragraphs, UTF-8 bytes and an estimated token count. Set a character limit to see how much room is left. It warns about trailing spaces, double spaces, tabs and invisible zero-width characters often copied from web pages, and one click tidies them.
- Runs in your browser
- No sign-up
- Free to use
How to use Prompt Character Counter
- Paste your prompt.
- Set a character limit if you have one.
- Read the counts and warnings.
- Tidy whitespace if needed.
Prompt Character Counter features
Visible characters
Emoji count once.
Bytes
UTF-8 size.
Limit check
Room left or overflow.
Hidden characters
Zero-width and spacing.
Tidy button
Cleans whitespace.
Private
Built in your browser; nothing is sent to an AI service.
When to use Prompt Character Counter
- Fields with character limits.
- API payload sizes.
- Cleaning copied text.
- Comparing prompt versions.
Prompt Character Counter FAQ
Why do counts differ between tools?
Some count code units, where an emoji counts as two; this tool shows both when they differ.
What are zero-width characters?
Invisible characters that can break matching, parsing or tokenisation.
Is the token count exact?
No, it is an estimate; use the Prompt Token Counter for exact OpenAI counts.
What do bytes matter for?
Some APIs and databases limit size in bytes, not characters.
Why do emoji count as more than one character in some tools?
Many systems count UTF-16 code units, and emoji often use two or more. This counter counts what a reader sees as one character.
What limit should I set?
The limit of the place you will paste the text – a model’s context window, an API field, a form or a social network.
Why is the token count an estimate?
Each model family splits text differently. For exact counts with OpenAI models, use the prompt token counter, which uses their real tokenizers.
Are line breaks counted?
Yes. Line breaks count as characters and add to the byte count, which matters for strict limits.
Measuring text precisely
Characters, bytes and tokens are three different measures of the same text. Limits in forms are usually characters, in storage often bytes, and in AI models tokens.
Cleaning invisible characters avoids subtle bugs when prompts are compared, cached or parsed.
Limits on prompts and posts are counted in different units. The counter shows characters as people see them (an emoji or an accented letter counts once), characters without spaces, words, sentences, lines, paragraphs, UTF-8 bytes and an estimated token count.
Bytes matter for APIs and databases with byte limits – non-Latin scripts and emoji take several bytes per character. Tokens matter for language-model limits and pricing; the estimate here is approximate, so use the token counter for exact counts with specific models.
Counting runs in your browser; the text is not uploaded or sent to an AI.
Different systems count differently: social networks usually count visible characters, databases and some APIs count bytes, and language models count tokens. Checking all three at once avoids surprises when text is cut off or rejected because it exceeds a limit you did not expect.