Can I count lines matching a specific pattern or prefix?

Yes. Enter a search term or regex pattern to count only lines that match — useful for counting error log entries, counting lines starting with a specific prefix, or counting occurrences of a pattern in a file.

Line Counter

Q: How does the Line Counter work in browser memory?

ToolJiffy splits the input text on newline characters (\n) and counts the resulting array length, also providing counts for non-empty lines, empty lines, and lines matching optional filter patterns — running 100% in browser memory.

Q: Why do developers need to count lines of code (LOC)?

Lines of code (LOC) is a basic software size metric used for effort estimation, project comparison, technical debt tracking, and code review scope assessment. Many engineering teams report LOC as part of sprint and release metrics.

Q: Can I count lines in a CSV file to determine record count?

Yes. For a CSV file with one record per line and a single header row, the non-empty line count minus 1 gives the exact data record count — faster than opening the file in Excel.

Q: Does the line counter handle both Windows (CRLF) and Unix (LF) line endings?

Yes. The counter normalizes both \r\n (CRLF/Windows) and \n (LF/Unix) line endings before counting, ensuring accurate results regardless of the file's origin operating system.

Free online line counter — sizing code files, CSV exports and lists.

100% Private — Runs entirely in browserInstant calculation & resultFree, no sign-up

Your text

Count lines in text, code files, and data exports instantly

Line counting is a fundamental operation for software development, data engineering, and content editing. Knowing the line count of a code file helps estimate code review effort. Knowing the line count of a CSV export lets you verify whether all expected database records were exported. Knowing the non-empty line count of a log file tells you how many events were logged. ToolJiffy Line Counter provides instant, accurate line counts with granular breakdown — total lines, non-empty lines, empty lines, and pattern-matched line counts — entirely in your browser.

Line counting use cases across disciplines

Software development (Lines of Code — LOC): LOC metrics help engineering managers estimate development effort, compare code size across modules, track technical debt accumulation over sprints, and scope code review assignments. Paste the contents of any source file to get an instant LOC count.
Data engineering (CSV record counts): A CSV file with a header row has exactly (total lines − 1) data records, assuming one record per line. Line counting catches truncated exports before they cause issues downstream.
Log analysis: Counting non-empty lines in a log file approximates the number of log events, while counting lines matching a regex pattern (e.g., ERROR) counts specific event types.
Content editing: Some content management systems limit content to a specific number of lines. Line counting lets editors verify compliance before submission.
Academic assignments: Poetry and code assignments sometimes specify line count requirements — line counting verifies compliance in seconds.

Breakdown metrics: total, non-empty, empty, and pattern-matched

ToolJiffy shows four line count metrics simultaneously:

Total lines: Every line including blank ones — equivalent to the POSIX wc -l command
Non-empty lines: Lines containing at least one non-whitespace character — equivalent to the actual content line count
Empty lines: Lines that are blank or whitespace-only — useful for detecting excessive blank line padding
Pattern-matched lines: Enter a search term or regex to count only lines matching the pattern

Browser-native line tokenization engine

ToolJiffy normalizes CRLF line endings by replacing \r\n with \n before splitting on \n. It applies a filter() pass for non-empty counting using line.trim().length > 0. Optional regex pattern matching uses new RegExp(pattern, 'i') applied per-line. All operations run synchronously in your browser for texts up to several million characters.

Step-by-step guide to counting lines

Paste your text or code: Copy and paste the content of your file, log, or export into the text area above.
View line counts: Review total lines, non-empty lines, and empty lines at a glance.
Filter by pattern (optional): Enter a search term to count only lines matching a specific prefix, keyword, or regex.

Frequently asked questions

How does the Line Counter work in browser memory?

ToolJiffy splits text on newline characters and counts the array length, also providing non-empty, empty, and pattern-matched line counts — running 100% in browser memory.

What is the difference between total lines and non-empty lines?

Total lines counts every line including blank ones. Non-empty lines counts only lines with at least one non-whitespace character.

Is my text data uploaded to any cloud server?

No. All line splitting and counting run 100% locally in your browser. Your text never leaves your device.

Can I count lines matching a specific pattern?

Yes. Enter a search term or regex to count only matching lines — useful for counting error log entries or lines starting with a specific prefix.

Why do developers need to count lines of code (LOC)?

LOC metrics help estimate development effort, compare code size, track technical debt, and scope code review assignments.

Can I count lines in a CSV file to determine record count?

Yes. Non-empty line count minus 1 (for the header row) gives the exact data record count in a CSV file.

Does the line counter handle both Windows CRLF and Unix LF line endings?

Yes. The counter normalizes both \r\n and \n before counting, ensuring accurate results from any operating system.

Is ToolJiffy Line Counter free without limits?

Yes. ToolJiffy is 100% free with unlimited text analysis, zero account registration, and zero server uploads.

Related text analysis tools

Count words with Word Counter, count sentences with Sentence Counter, remove empty lines with Remove Empty Lines, or analyze word frequency with Word Frequency Counter.