Efficiently remove duplicate lines from text while preserving the original line order.
Enter text to see the joined result
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When processing log files or data lists, duplicate lines not only waste space but also interfere with analysis. This tool automatically removes duplicate lines by comparing text line by line (separated by line breaks), keeping only the first occurrence of each line. A "line" refers to a text snippet separated by a line break ( ). It supports processing any text content, including special characters.
Q: How are lines with tabs handled?
By default, they are treated as regular characters. Checking "Remove leading and trailing whitespace" will delete tabs at the beginning and end of the line.
Q: Will removing duplicate lines change the original line order?
No. This tool uses a stable deduplication algorithm that strictly preserves the original order of the first occurrence of each line.
We recommend processing no more than 100,000 lines of text at a time. Full-width spaces are not automatically recognized as whitespace. The processed result will retain the original line break format.
When deduplicating code comments, we recommend selecting the "Remove leading and trailing whitespace" mode to avoid formatting interference. Typical input/output example:
Input: // TODO
/* comment */
// TODO
Output (Remove leading and trailing whitespace mode): // TODO
/* comment */
