What counts as a comment line?

A line is counted as a comment if, after trimming leading whitespace, it starts with a comment marker for the detected language (e.g. //, #, --, ). Inline comments on code lines do not make the line a comment line.

What counts as a blank line?

A line that contains only whitespace (spaces, tabs, or is completely empty) is counted as blank.

How does language auto-detection work?

The tool scans the pasted code for characteristic patterns: shebang lines, common keywords, import/def/function syntax, and comment styles. It assigns a confidence score to each candidate language and picks the highest scoring match. You can also override the detected language manually.

What is LOC and why does it matter?

LOC (Lines of Code) is the count of non-blank, non-comment lines — the executable or declarative statements in the file. It is a rough proxy for code complexity and is used in metrics like comment density (comment lines / total lines) and code churn.

Can I paste multiple files?

You can paste the concatenated content of multiple files into the textarea. The counters reflect the aggregate totals. For per-file stats, paste each file separately.

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Code Line Counter

Count total, blank, comment, and code lines in any pasted code with language auto-detection.

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About this tool

The Code Line Counter analyses pasted source code and breaks it down into four categories: total lines, blank lines, comment lines, and actual code lines. It automatically detects the programming language based on syntax patterns and applies the correct comment rules — double-slash (//) for JavaScript, TypeScript, Java, C, C++, C#, and Swift; hash (#) for Python, Ruby, Shell, and YAML; double-dash (--) for SQL and Lua; block comments (/* … */) for C-family languages; and HTML/XML comments (). Results are displayed with progress bars showing the proportion of each line category, making it easy to gauge comment density and blank-line ratio at a glance. Useful for code review, metrics reporting, estimating documentation coverage, or satisfying coding standards that require a minimum comment ratio.

How to use

1 Paste your source code into the textarea.
2 The tool auto-detects the language and displays a label.
3 Override the language using the dropdown if detection is incorrect.
4 Read the four counters: Total, Blank, Comment, and Code lines.
5 Check the progress bars to visualise the proportion of each category.

Frequently Asked Questions

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