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Remove Lines by Keyword

Delete every line that contains a specified keyword. Six matching modes: Contains, Case Insensitive, Starts With, Ends With, Exact Match, and Regex. Quick presets for comments, debug lines, logs, tests, and more.

Remove Lines by Keyword

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Keywords to Filter

Quick Presets:

No keywords selected. Add some above or use a preset.

Input Text
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Filtered Text

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What Is the Remove Lines by Keyword Tool?

The Remove Lines by Keyword Tool scans text line by line and removes every line that matches at least one keyword in your list. Six matching modes cover simple text contains, case-insensitive search, line-start/end matching, exact full-line match, and full regex patterns. A live stats panel shows how many lines were removed and what percentage matched. Everything runs in your browser — no server, no login.

How to Filter Lines by Keyword

  1. Add keywords manually or click a Quick Preset (Comments, Debug Lines, Log Lines, Test Lines, TODO/FIXME, Error Lines).
  2. Paste your text — code, log files, CSV data, or any multi-line content.
  3. Choose a Matching Mode — "Contains Keyword" is the most common choice for general filtering.
  4. Click Copy or Download to save the filtered output.

Where Can You Use the Remove Lines by Keyword Tool?

Remove Debugging from Code

Strip every console.log, print(), and debug() statement before shipping a release — use the Debug Lines preset and Contains mode.

Clean Log Files

Filter out INFO or WARN lines from a log dump to see only ERROR and FATAL entries — faster than grepping in a terminal, with no command-line required.

Data Import Cleanup

Remove header lines, comment lines, or empty data rows from CSV or TSV exports before importing into another system or database.

Code Comment Stripping

Use the Comments preset with Starts With mode to remove //, #, and -- comment lines from any code file before sharing or publishing.

Matching Modes Explained

  • Contains Keyword: Removes any line where line.includes(keyword) is true — case-sensitive.
  • Case Insensitive: Same as Contains but converts both line and keyword to lowercase before comparing — catches DEBUG, Debug, and debug equally.
  • Starts With: Trims the line first then checks trimmedLine.startsWith(keyword) — ideal for removing comment lines like // or #.
  • Ends With: Trims the line and checks trimmedLine.endsWith(keyword) — useful for removing lines that end in specific markers.
  • Exact Match: Removes lines where the entire trimmed line equals a keyword — prevents short keywords from matching long lines.
  • Regular Expression: Treats each keyword as a regex pattern using new RegExp(pattern).test(line). Patterns are compiled once for performance. Invalid patterns fall back to contains-matching.

Best Practices and Limitations

All processing runs locally in your browser — no data is uploaded to any server, making it safe for private code, internal logs, and confidential exports.

Short keywords in Contains mode match substring occurrences — the keyword log also matches "catalog", "analog", and "ecology". Use Starts With or Exact Match to be more precise, or prefix keywords like LOG: instead. In Case Insensitive mode, error matches Error, ERROR, and error — switch to it when your log levels are inconsistently capitalised.

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Frequently Asked Questions

What is the difference between Contains and Exact Match modes?+

Contains mode removes any line where the keyword appears anywhere within it — "debug" would remove "console.debug(x)". Exact Match only removes lines where the entire trimmed line equals the keyword exactly — useful for removing marker lines like "TODO" that stand alone.

How do I remove all console.log lines from JavaScript code?+

Add "console.log" as a keyword, choose Contains Keyword mode, and paste your code. Every line containing console.log will be removed. For a broader sweep of all console methods, also add "console.error", "console.warn", and "console.debug".

Can I use multiple keywords at once?+

Yes. Add as many keywords as you need using the keyword input or Quick Presets. The tool removes any line that matches at least one keyword — lines must match ANY keyword to be removed (OR logic, not AND).

How does Regex mode work and when should I use it?+

Regex mode treats each keyword as a JavaScript regular expression tested against each line. Use patterns like ^Error: to remove lines starting with "Error:", or d{3}-d{4} to remove lines containing phone-number patterns. Invalid regex patterns fall back to contains-matching.

Will this modify lines that are kept — only removing matching lines entirely?+

Yes. This tool only removes complete lines. If a line contains a keyword, the entire line is deleted from the output. If you need to remove a word from within a line without deleting the whole line, use the Find and Replace Tool instead.