Filter text lines
Keep or remove lines containing a specific piece of text.
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How we handle your data →How to use this tool
- Paste one entry per line.
- Enter a literal search and choose keep or exclude.
- Check the count, order and letter-case differences.
An example you can verify
Separate errors from a log without modifying matching lines.
Example input
ERROR: A INFO: B error: C
Expected result
ERROR: A error: C
2 of 3 lines remain. Exclude mode retains only INFO: B.
Keep only lines containing a word
Matching is literal and can also match part of a word. Keep or exclude matching lines, choose case sensitivity and check the count. Order and duplicates are preserved.
Filter text lines: uses and practical guidance
Filtering lines keeps or excludes entries according to a text match. It can separate project references, locate messages containing a label or remove unwanted lines from a list. Prepare one complete entry per line and decide first whether matching lines should remain or be discarded. The same search can produce opposite groups depending on that selection, so verify the mode before applying it to a large block of input.
Matching follows the available options, including whether uppercase and lowercase are distinguished. A short sequence can occur inside a longer word and retain more lines than expected. Use a sufficiently specific fragment and test a sample containing one line that should qualify and one that should not. Spaces belong to the input: a query with surrounding spaces may fail to match a label directly beside punctuation or at the edge of a line.
The result remains a textual list. The tool does not understand CSV record structure or interpret a JSON field, so a line containing the term in a different column may also qualify. Prepare a representation that identifies the relevant field precisely when the criterion depends on one particular value. Filtering does not remove duplicates or sort surviving entries; it keeps or excludes complete lines according to the selected matching rule.
Inspect a match near the beginning, another near the end and an entry expected to be excluded. Keep the original list when you may need the opposite group or an explanation of what was removed. Find and replace changes line contents, while Remove duplicate lines addresses repetition. If filtering returns no entries, review the query and options before concluding that no relevant information exists. A mismatch in capitalization or separators can be enough to produce an empty result.
Settings and limits
Paste a list, enter the search text and choose whether to keep or exclude matches. Matching is literal: dots, brackets and other symbols are not regular expressions. You can enable case sensitivity. Order, duplicate lines and whitespace are preserved. Maximum 1 million text characters and 1,000 search characters.
Frequently asked questions
What happens to blank lines?
They cannot contain a nonempty search string. Keep mode excludes them; exclude mode retains them. A result with no matching lines can be empty.
Are my data stored on a server?
No. Content and files are processed in your browser without an account. Closing the page loses unsaved results.
Is it free, and do I need to sign up?
Yes, it is free. You do not need to sign up, create an account or install an app, and there is no daily quota: open the tool and use it. The only limits are file sizes, which protect your device’s memory.
Is my data sent to any server?
No. What you type or paste is processed in your browser’s memory and is not sent to any server. You can check it in the browser’s Network tab or by going offline after the page has loaded.