Text Character Count and UTF-8 Size Calculator
Count UTF-8 bytes, UTF-16 units, Unicode code points and grapheme clusters with explicit text transformations.
YOUR CALCULATION
Result
β
Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Apply the chosen line-ending and Unicode normalization transformations, then count encoding bytes, Unicode scalar/code-point iterations and user-perceived grapheme clusters. All work runs in the browser.
UTF-8 size=encoded transformed text bytes+optional 3-byte BOM; UTF-16 size=2Γcode units+optional 2-byte BOM
Worked example
The text AΓ©π has 4 UTF-16 code units, 3 code points and 3 grapheme clusters, but 7 UTF-8 bytes without a BOM. An e plus a combining accent can have two code points in one grapheme.
Assumptions and input details
Maximum input 100000 UTF-16 code units. A grapheme cluster can include multiple code points; it is not a font glyph or a universal display-width measure. Browser Intl.Segmenter supplies grapheme boundaries. UTF-16 byte count excludes any file container; endianness does not change size. Unpaired surrogates, if present, encode as U+FFFD in UTF-8. No HTML, JSON or URL escaping, compression or transport overhead is included. Text is never uploaded.
References: Unicode: text segmentation
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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