Sort Lines

The Sort Lines tool arranges text lines in alphabetical order (A to Z or Z to A), numerical order, by line length, in random (shuffled) order, or reversed — whatever arrangement you need. It sounds simple until you realize how often the task arises: a long list of email addresses needs alphabetizing before deduplication, URLs from a scrape need sorting for batch processing, imported data needs canonicalizing before comparison, a code file has scrambled import statements that should be tidied, a mixed list of numeric IDs and text needs natural sorting that handles embedded numbers correctly.

This tool handles every common sorting need in one interface. Paste lines, pick a sort mode, copy the result. Case-sensitive and case-insensitive modes available. Natural sort order handles embedded numbers (so file2 sorts before file10, not after, matching the Windows and macOS file browser convention). Locale-aware sorting uses the correct alphabetization for accented characters (German ß, Spanish ñ, French é). Duplicate removal and trimming of leading/trailing whitespace are optional post-processing steps. Works with lists of any size — thousands of lines process in milliseconds entirely in your browser.

Sorting text lines looks trivial — JavaScript has a built-in sort method — but the default behavior has enough pitfalls that a purpose-built tool is often worth the extra friction.

Default lexicographic sort compares character code points. This puts uppercase letters before lowercase (B before a) and digits before all letters (1 before A), which rarely matches human expectations. Case-insensitive sort uses .toLowerCase() on both sides of the comparison, giving the A-Z order most people want.

Locale-aware sorting uses Intl.Collator to produce correct ordering for the target language. In Swedish, å sorts after z; in German, ä sorts near a (standard) or near ae (DIN 5007); in Spanish, ñ sorts after n. The browser provides these via Collator — this tool exposes locale choice so you get the correct alphabetization for your content.

Natural sort (sometimes called version sort or human sort) treats embedded numeric substrings as numbers for comparison. So item-2, item-10, item-100 sort in that order, not item-10, item-100, item-2 (which is what lexicographic sort produces because 1 < 2 at the character level). Natural sort matters for file listings, version numbers, and any list where numbers appear within strings.

Numeric sort treats each line as a number and sorts by numeric value. Useful for lists of pure numbers, phone numbers (though leading-zero preservation matters there), or IDs. Lines that are not numeric go to the end by convention or trigger an error.

Sort by length is straightforward (sort by line.length), used for visual arrangement of text or finding the longest/shortest entries quickly.

Random sort uses the Fisher-Yates shuffle algorithm for uniform distribution. Standard JavaScript sort with Math.random() in the compare function does not produce a uniform shuffle — a known gotcha. The tool uses Fisher-Yates internally.

Removing duplicates after sorting uses a simple adjacent-comparison pass since equal items are adjacent after sort. Without sort first, you can use a Set to deduplicate in any order but lose the original sequence.

For very long lists (hundreds of thousands of lines), the browser handles them in-memory with minor delay. Lines over one million can cause memory pressure — split into chunks if you hit problems.

Compared to the Unix sort command, this tool is accessible without a terminal and handles edge cases (natural sort, locale awareness) via a simple UI. The CLI wins for scripting and very large files; this tool wins for interactive one-off tasks.

Compared to spreadsheet sort (Excel, Google Sheets), this tool is faster for simple line sorting — no need to open a spreadsheet, set up columns, or save. For multi-column sort or table-like data, a spreadsheet is the better choice.

Compared to text editor sort plugins (VS Code, Sublime), this tool gives the same result without requiring the plugin to be installed. Editor plugins are convenient when you are already editing; this tool is convenient when you are not.