Processed in your browser

Line Deduplicator & Sorter

Keep the first occurrence while matching lines case-sensitively or case-insensitively. Preserve original order or sort ascending or descending, and decide whether an empty line is data.

Processed in your browser
0 / 1,000,000
Processed lines

Tool guide

What is Line Deduplicator & Sorter?

Line Deduplicator and Sorter processes lists, logs, keywords, and other line-based text. You choose case sensitivity, blank-line handling, and sorting, while the first original occurrence is retained. Whitespace is not silently trimmed, so comparison rules are explicit and results remain easy to audit. Common workflows include the following. Clean duplicate IDs, addresses, or keywords copied from another system. Remove repeated log lines while preserving first-seen order. Sort deduplicated text using locale-aware comparison. The page also documents input boundaries, output behavior, and practical cautions so you can review the result before putting it into an application, configuration, test, or production workflow.

When to use it

  • Clean duplicate IDs, addresses, or keywords copied from another system.
  • Remove repeated log lines while preserving first-seen order.
  • Sort deduplicated text using locale-aware comparison.

How to use it

  1. Paste one item per line.
  2. Choose case, empty-line, and ordering rules.
  3. Remove duplicates, sort if requested, and copy the output.
  4. Load one of the realistic examples first to verify the selected options and processing direction before replacing it with your own data.
  5. Review the output, status message, and documented limits; copy, download, or continue only after the result matches your expectation.

Runnable examples

The “Example 1” and “Example 2” buttons load the matching inputs. They cover different structures, directions, or boundaries and can be run directly in the workspace.

Example 1

JSON Formatter
Base64 Encoder
json formatter
Regex Tester
Base64 Encoder

UUID Generator

Example 2

develop
main
Develop
preview
main
production
Preview

Input rules

  • Each line is treated as one independent item.
  • Leading and trailing whitespace remains part of the line.
  • Case and blank-line comparison follow the selected options.
  • Text input is counted before processing and is limited to 1,000,000 characters on this page; file modes apply the separate file limit shown in the workspace.
  • Lines are not trimmed or normalized.

Output rules

  • Duplicate items retain the first original spelling.
  • Without sorting, first-seen order is preserved.
  • Sorting uses Intl.Collator rather than raw byte order.
  • Output reflects only the current input, direction, and options; rerun after changing a mode or value instead of treating an earlier result as current.
  • Case-insensitive matching follows browser locale behavior.

Limitations and cautions

  • Lines are not trimmed or normalized.
  • Case-insensitive matching follows browser locale behavior.
  • Sorting may differ slightly across browser Unicode data versions.

How your data is handled

Line splitting, comparison, deduplication, and sorting all run in the browser with no upload.

FAQ

Which duplicate spelling is kept?

The first occurrence is kept, even in case-insensitive mode.

Are spaces trimmed?

No. Leading and trailing spaces remain part of each line.

Is sorting byte-based?

No. Intl.Collator provides locale-aware, numeric-friendly ordering.

Which spelling is retained in case-insensitive mode?

The first original line is kept; later lines that differ only by case are removed as duplicates.

Are lines with different surrounding spaces duplicates?

No. Leading and trailing spaces remain part of each line; clean whitespace first if it should be ignored.

Can I restore the original order after sorting?

The page does not save a position map. Choose Preserve or keep a copy of the source before sorting.

Updated: 2026-08-02