How to extract matching lines from text online
Find lines containing a keyword in a large text file
Extract exact or partial text matches
Extract matching lines with case sensitivity
Copy or download filtered lines
Example: extract lines that contain error
Extract matching lines without uploading a file
Features explained
Query-based line filtering
Enter a word or phrase in query to select matching lines. The default query is an empty string.
Configurable matching rule
The matchMode option determines how a line is compared with the query. The default value is contains; other supported values require verification in the matching helper.
Case sensitivity control
The caseSensitive option defaults to false, so case-sensitive matching isn't enabled by default.
Copy to clipboard
Use Copy to copy the extracted output. The interface also has a Copied! label for its copied state.
Download results
Use Download to save the extracted lines. The generated filename and file type aren't confirmed by the supplied code.
Load an example
Load Example provides a way to populate sample text for trying the tool.
Clear current text
Clear is available to reset the current work in the interface.
Client-side processing
The scanned processing logic filters the lines in the browser-side code without a detected fetch or API call for the operation.
What can you use it for?
Filter application logs
Keep lines that contain a search term such as error or warning when reviewing text logs.
Find records in exported text
Extract matching entries from a pasted list of names, identifiers, or other text records.
Prepare keyword-based text lists
Keep lines containing a chosen keyword before copying the filtered list into another application.
Review support notes
Search pasted notes for a relevant word or phrase instead of reading every line manually.
Separate relevant research notes
Extract lines containing a topic name from a collection of plain-text notes.
Tool information
| Tool mode | extractMatchingLines |
|---|---|
| Default query | Empty string |
| Default match mode | contains |
| Default case sensitivity | false |
| Input assumption | Plain text, separated into lines |
| Output | Matching lines joined with newline characters |
| Processing | Client-side; no fetch/API call detected in the scanned processing code |
Benefits
- Keeps matching lines while excluding nonmatching lines.
- Lets you configure the query and matching behavior.
- Starts with contains matching and case sensitivity disabled.
- Provides Copy, Download, Load Example, and Clear controls.
- Returns the selected lines separated by newline characters.
Limitations
- The tool's matching behavior depends on the selected matchMode and the matching helper implementation.
- The available code doesn't establish every supported matchMode value or its precise rules.
- The default query is empty, so the output depends on how the matching helper handles an empty query.
- No maximum input length or file size is established by the supplied code.
- The download filename and extension aren't confirmed.
- Client-side processing in the scanned code doesn't prove that every part of the website operates offline or that no other site data is collected.
How text processing works
The scanned implementation performs line filtering in client-side code, and no fetch or API call was found in the processing path. This supports describing the filtering operation as client-side. It does not independently verify the website's broader privacy practices, analytics, storage, or network behavior outside this code.
Tips
- Enter a specific word or phrase in the query option to narrow the output.
- Start with contains when you want to find lines with a term anywhere in the line.
- Keep caseSensitive set to false when uppercase and lowercase differences shouldn't matter.
- Use Load Example to try the tool before pasting your own text.
- Check the output before using Copy or Download.
- For a large text file, paste its text into the input area; the supplied code doesn't confirm direct file importing.
Frequently asked questions
How do I extract lines containing a specific keyword?
Enter your text, set query to the keyword, and use the contains matching rule. The tool checks each line and joins matching lines with newline characters. Review Matching Lines before copying or downloading the result.
Can I extract matching lines from a large text file?
Yes. You can paste text from a large file into the input area and filter its lines. The supplied code doesn't specify a maximum text length, so it doesn't establish a guaranteed file-size limit or performance level.
Does matching ignore uppercase and lowercase letters?
By default, caseSensitive is false. The exact comparison behavior depends on the matching helper and the selected matchMode. Check the helper implementation if you need to confirm how uppercase and lowercase letters are compared.
How can I extract matching lines in my browser?
Use the input area and the query and matching options. The scanned implementation filters lines in client-side code, and no fetch or API call was found in that processing path. This does not establish that the entire website works offline.
Can I copy the extracted lines into another app?
Yes. Select Copy to copy the Matching Lines output to your clipboard. The interface also includes a Copied! label. You can then paste the extracted text into another application that accepts text.
Can I download matching lines as a text file?
Yes. The interface includes Download for saving the output. The supplied code doesn't establish the generated filename or extension, so a specific file format can't be guaranteed from this information alone.
What happens when the search query is empty?
The query option defaults to an empty string. The final result depends on how the matches helper handles an empty query with the selected matching rule. That helper's behavior isn't fully shown in the supplied code.
Can I find a phrase instead of a single word?
Yes. The query is converted to a string before matching, so you can enter a phrase as well as a single word. The exact behavior for spaces and phrase boundaries depends on the selected matching rule.
Does the extract matching lines tool upload my text?
The scanned filtering code runs on the client side, and no fetch or API call was found in the processing path. That supports client-side processing for this operation, but it isn't a complete audit of network activity or data handling across the website.