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Real-time Metrics
Counts lines, words, characters, paragraphs, and reading time with a 300ms debounce.
简体中文
Line Counter 工作台
直接粘贴文本、上传文件、对比两段内容，并导出统计结果。
Static mode keeps processing in the browser. URL fetching was removed to avoid a backend dependency.
Ready.
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Text, Files, and URLs
Paste text, upload code or document files, or fetch a remote page into the editor.
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Exports + History
Copy JSON, download CSV or PDF, and keep the latest local analyses without leaving the page.
Use Cases
Built for developers, writers, and students
Developers
Count source lines, spot comment-heavy modules, and prep quick reports before shipping.
Writers
Track manuscript line counts, paragraph density, and reading time for editors and clients.
Students
Measure assignment formatting, compare drafts, and keep pasted research notes clean.
SEO Content
什么是 Line Counter？
Line Counter 用来统计一段文本或代码中包含多少行。开发者可以用它查看源码规模，写作者可以用它控制版式与篇幅，学生可以用它检查作业格式。一个好用的行数统计工具不应只看总行数，还应同时显示单词数、字符数、空行数和段落数。
How it works
- 1Paste text, upload a supported file, or fetch content from a URL.
- 2Choose text mode or code mode depending on the input.
- 3Review live metrics including total lines, words, characters, paragraphs, and reading time.
- 4Copy results, export a report, or share a compressed link.
本地处理，更快更轻
核心统计逻辑直接在浏览器中运行，大文本通过 Web Worker 处理，适合静态部署，也减少输入时的卡顿。
Static export ready
• Client-side counting
• Web Worker for heavy text
• Local history + exports
• No server runtime requiredFAQ
常见问题
How do I count lines in a text?
Paste or type your content into the editor and the line count updates automatically. You can also upload a text file from your device.
What is a line counter used for?
A line counter helps developers, writers, and students measure how many lines a document contains so they can follow formatting limits, analyze code, or compare drafts.
How to count lines in code?
Switch to code mode to estimate the programming language and separate code lines from comment lines and blank lines.
What's the difference between lines and paragraphs?
A line is a single row separated by a line break, while a paragraph is a block of text usually separated by one or more blank lines.
Can I count lines in a PDF file?
This version focuses on text-based files such as TXT, MD, JS, PY, and many other plain-text formats. For PDF input, extract the text first and then paste or upload the text output.
How to count blank lines separately?
The stats panel reports total lines, non-empty lines, and empty lines independently so you can measure whitespace precisely.
Is there a line counter for programming?
Yes. Code mode highlights code lines, comment lines, and a detected language so you can inspect source files more accurately.
How accurate is an online line counter?
For plain-text content it is exact because the tool counts normalized line breaks directly. Code metrics are heuristic-based for comments and language detection.
Tools
相关工具
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Word Counter
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Sentence Counter
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Character Counter
Track characters with and without spaces for tweets, ads, and UI copy.
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Blank Line Remover
Remove empty lines from pasted text, logs, and code snippets.
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Remove Line Breaks
Join wrapped lines into paragraphs or replace newlines with custom separators.
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Text Diff Tool
Compare two texts side by side and highlight added, removed, and changed lines.
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Line Sorter
Sort lines A-Z, Z-A, or randomize them for lists and datasets.
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Duplicate Line Remover
Remove duplicate lines while preserving the first occurrence.
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Line Number Adder
Prefix each line with a sequential number for review or sharing.
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Text to Lines
Turn sentences or comma-separated text into one item per line.
Blog
教程与指南
10 min read
How to Count Lines in AWK (NR, FNR, and Why They're Different With Multiple Files)
Count lines in AWK with END{print NR}, per-file FNR patterns, RS record separator changes, and match counting. Covers NR vs FNR, GNU awk ENDFILE, nonblank-line counting, and when wc -l is the better tool.
13 min read
How to Count Lines in a File in C (And Why `fgetc` Is 9x Slower Than `fread`)
Count lines in a file in C — fgets, fread, mmap, and the large performance gap between them. Covers `wc -l` internals, Windows vs Linux portability, long-line traps, and production-ready counting patterns for large files.
12 min read
How to Count Lines in a File in C++ (And Two Classic Traps That Catch Everyone)
Count lines in a file in C++ using ifstream, istreambuf_iterator, fread, and mmap. Covers the while(!eof()) off-by-one trap, the single-pass istreambuf_iterator reset issue, and why newline-byte counters must fix the missing final newline case.
9 min read
How to Count Lines with grep (-c Flag, Total Lines, and the Multi-File Advantage)
Count lines with grep using -c for matches, grep -c '' for total lines, and grep -vc for non-matching lines. Covers multi-file per-file counts, GNU grep vs BSD grep compatibility, missing trailing newline behavior, and grep vs wc -l tradeoffs.
14 min read
How to Count Lines in a File in Haskell (And Why `lines ""` Is Not the Real Trap)
Count lines in a file in Haskell — readFile, lines, Data.ByteString, and strict vs lazy IO. Covers the `lines ""` myth, final-newline off-by-one bugs, Lazy IO file descriptor leaks, and high-performance streaming with ByteString.
14 min read
How to Count Lines in a File Using Kotlin (And the useLines Sequence Trap Nobody Documents)
Count lines in a file using Kotlin — File.readLines, useLines, BufferedReader, and Coroutines Flow. Covers the useLines Sequence escape trap, OOM risks, and Android/Spring Boot patterns with benchmarks.
Workflow Fit
Browser-based text tools for real workflow scenarios
Pick the tool that matches the job instead of forcing every text task through the same editor.
Line Counter is a privacy-first line counter for developers, writers, students, and operations teams who need accurate text metrics without opening a heavy desktop app. Start with the main line counter when you need structure, then move into the online word counter for students and editors or the character counter for SEO writers when length limits matter more than raw lines.
Cleanup workflows are covered too. Teams use the duplicate line remover for spreadsheet cleanup, the text to lines converter for data analysts, and the line sorter for CSV exports and lists when raw exports need one fast pass before import, review, or publishing.
Review-heavy jobs can add references with the line number adder for legal review and debugging, while the blank line remover keeps pasted drafts and machine output readable. If you want step-by-step examples, open the text workflow guides, browse the full tools directory, or send a request through the contact page.