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Remove Lines by Keyword

Remove whole physical lines matching any saved keyword or Unicode regex pattern. Apply, review retained counts, then copy or download LF text.

Built by Saurabh Kumar

Quick Answer

Filter independent physical text lines with six OR-matching modes. Starts/Ends/Exact trim comparison edges only; retained contents stay. Regex syntax errors are visible. Apply runs in a cancellable worker with a two-second timeout; this is not a code or multiline CSV parser.

Literal token presets (add to saved keywords)
Matching mode

Remove lines matching any saved keyword. Starts/Ends/Exact trim only comparison edges; retained text stays. CRLF/LF/CR input becomes LF output. Regex: case-sensitive Unicode pattern text, without slash delimiters. Limits: 100 keywords, 1,000 units each, 1,000,000 input units / 20,000 lines.

Click Apply to review a result. Background requests stop after two seconds; edits or Cancel stop pending work and clear the old output. Your input stays unchanged.

No current result. Apply after changing input or settings.

If Copy fails, select the output and copy manually. An empty result is shown in the counts; there is no nonempty text to export.

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Find and Replace ToolRemove Empty LinesSort Lines ToolChange Case ToolFlip List ToolCount Words/Characters - Stats ToolAdd Prefix/Suffix - Line EditorAdd/Remove Line Breaks

What Is Remove Lines by Keyword?

Remove whole physical lines that match any saved keyword or regex pattern. Retained line contents stay unchanged; separators become LF. Review the remaining and removed counts before exporting.

How to Filter Lines

  1. Paste independent text records, such as a log excerpt.
  2. Type a nonblank keyword and press Add or Enter. Presets add literal tokens; choose a literal mode for them.
  3. Select a matching mode and click Apply Filter.
  4. Review the output and counts. Copy or Download TXT if the result has text.

How the Matching Modes Work

Contains is case-sensitive substring matching. Case Insensitive compares lowercased strings, not universal locale-aware case folding. Starts With, Ends With and Exact Match trim line edges for comparison only. All modes use OR: one matching keyword removes that entire line. Keyword entry trims its edges; use regex escapes to target edge spaces.

Regex takes JavaScript pattern text without slash delimiters, using Unicode mode and case-sensitive matching against each physical line. Invalid syntax fails the entire operation visibly, with no literal fallback. Apply runs in a background worker; edits, Cancel or a two-second timeout terminate that request. A worker-load failure keeps the input and gives an error. Timing includes startup and does not certify browser responsiveness.

Example: A Short Keyword Can Match Too Much

Use the keyword log with these three original lines.

Comparison scope changes which lines disappear
Input lineContainsExact Match
catalogRemovedKept
log RemovedRemoved
LOGKeptKept

When to Filter Whole Lines

Hide a known severity prefix in a copied log excerpt.

Remove exact placeholder rows from a plain list.

Prepare a reviewed text-only subset using several independent keywords.

Common Mistakes

A comment token can also occur inside a URL or string. This is not a code-comment parser, syntax-preserving debugger cleanup or multiline CSV filter. Presets are convenience tokens, not safe deletion rules. An empty output may retain one empty item: for input A followed by LF, removing A leaves one retained item and one removed item. Counts come from records, not output truthiness.

Tips for a Reviewable Filter

Keep a backup and choose Exact Match or a specific prefix when broad substrings would overmatch. Clear All resets keywords and mode. No keywords keeps all original items while normalizing separators. Limits are 1,000,000 input UTF-16 units, 20,000 lines, 100 keywords and 1,000 units per keyword. Use Find and Replace to edit text within lines, or Remove Empty Lines for a dedicated blank policy. See Unicode regex semantics before using advanced patterns.