How do I use this tool?

Simply paste your text, enter the pattern or text you want to match, select your matching options (case sensitivity, regex, etc.), and the tool will automatically remove matching lines.

What happens to non-matching lines?

Non-matching lines are preserved in their original order. Only lines containing the specified pattern are removed (or kept, if using invert match).

Can I process large amounts of text?

Yes, the tool is optimized for performance and can handle large text files efficiently, processing them line by line to maintain good performance.

What is case-sensitive matching?

Case-sensitive matching distinguishes between uppercase and lowercase letters. For example, 'Test' and 'test' are treated as different patterns when case sensitivity is enabled.

How does regex support work?

Regular expressions (regex) allow complex pattern matching using special characters and rules. For example, \d+ matches any sequence of digits, and .* matches any characters.

What is invert matching?

Invert matching reverses the tool's behavior - instead of removing lines that match the pattern, it removes lines that don't match, effectively keeping only matching lines.

What is whole word matching?

Whole word matching ensures the pattern matches complete words only, not parts of words. For example, searching for 'cat' won't match 'category' when whole word matching is enabled.

How can I clean log files?

Use the tool to remove log entries containing specific error codes, timestamps, or irrelevant information, making log analysis more efficient.

Can I filter data exports?

Yes, you can remove rows containing specific values or patterns from CSV/TSV data, helping clean exported data before analysis.

How do I remove spam or unwanted content?

Enter common spam phrases or patterns to remove lines containing unwanted content from text data, like comment logs or message exports.

Can I use it for code cleaning?

Yes, use it to remove comments, debug statements, or specific code patterns from source code files, helping clean up development files.

How are empty lines handled?

Empty lines are preserved by default but can be filtered using appropriate patterns or regular expressions if needed.

Is there a line length limit?

The tool can handle lines of any length, though very long lines (>100,000 characters) might impact performance.

How does Unicode support work?

Full Unicode support means the tool can process text in any language and handle special characters correctly in both patterns and content.

What's the maximum file size?

While there's no strict limit, browser memory constraints typically allow processing files up to several megabytes efficiently.

Remove Lines Containing

A powerful tool to remove lines containing specific text or patterns from your content. Perfect for cleaning logs, filtering data files, and processing text with advanced pattern matching options.

Case Sensitive

Regex Support

Whole Words

Invert Match

Unicode Support

Enter text to process...

Matching Options

Case SensitiveWhole Words

Advanced Options

Use RegexKeep Matching Lines

Features

Case sensitive/insensitive matching
Whole word matching
Regular expression support
Invert match (keep matching lines)
Preserves empty lines
Unicode support
Handles special characters
Undo/redo support

Instructions

Paste or type text in the editor
Enter the text to match
Select matching options
Click "Remove Lines"
Copy the filtered result

Interesting History

The concept of pattern matching and line filtering dates back to the early days of Unix in the 1970s. The 'grep' command, created by Ken Thompson, revolutionized text processing by introducing regular expressions for pattern matching. The name 'grep' comes from the ed command g/re/p (globally search for a regular expression and print). This fundamental concept has evolved into modern text processing tools, making complex pattern matching accessible to everyone.

Other Text Tools

Add Repeats Character Counter Column Extractor Find and Replace Case Converter Remove Duplicates Add Prefix/Suffix Remove Empty Lines Remove Extra Spaces Remove Accents Remove Lines Containing Remove Punctuation Sort Lines

Frequently Asked Questions

Basics

Basic concepts and usage

Key Features

Pattern Matching

Simple text pattern matching
Regular expression support
Case-sensitive/insensitive options
Whole word matching capability

Processing Options

Invert match functionality
Multi-line text processing
Unicode text support
Large file handling

User Experience

Real-time preview
Undo/redo support
Copy to clipboard
Clear formatting options

Advanced Features

Multiple pattern filtering
Line number preservation
Empty line handling
Batch processing support