Find Unique Lines
Paste text and keep only the lines that appear exactly once — repeated lines are dropped entirely (like uniq -u). Optional case-insensitive and whitespace-trim matching. Runs in your browser; nothing is uploaded.
About this tool
Find Unique Lines scans pasted text and keeps only the lines that appear
exactly once — every line that repeats is dropped entirely. This is the
classic uniq -u behaviour: not deduplication (which keeps one copy of each
line), but one-off detection.
- Ignore case — treat
Foo,foo, andFOOas the same line, so a value that recurs in mixed case is correctly excluded. - Trim whitespace — ignore leading/trailing spaces and tabs when comparing,
so
itemanditemcount as the same line.
Unique lines are returned in the order they first appeared. The tool also reports the total number of lines and the number of distinct lines. Everything runs locally in your browser via WebAssembly — your text is never uploaded.
Handy for
- Finding values that occur in one list but not another (paste both, keep the one-offs).
- Spotting outliers or typos that appear only once in an export or log.
- Isolating rows that didn't get duplicated by a faulty merge or join.
Want to count how often each line repeats, or list the duplicates instead? Use a duplicate-finder tool; this one keeps only the lines that appear once.
FAQ
How is this different from removing duplicates?
Deduplication keeps one copy of every line; this tool (like uniq -u) keeps
only lines that occur exactly once and drops every repeated line entirely.
If a value appears twice, it won't be in the output at all.
Is the comparison case-sensitive?
By default, yes — Foo and foo are different lines, so if each appears once
they are both kept. Turn on Ignore case to treat them as the same line, in
which case the pair counts as a repeat and both are dropped.
A line looks unique in my text but was dropped — why?
Check the normalization options: with Trim whitespace on, item and
item compare equal, and with Ignore case on, NYC and nyc do too. A
line that repeats only under normalization is excluded as a duplicate.
What order do the results come out in?
The order the unique lines first appeared in your input — nothing is sorted. The result also reports the total line count and the number of distinct lines.
Developer & Automation Access
Run it from the terminal
Same engine as this page, headless — via the gizza CLI:
gizza tool find-unique-lines "Paste lines to find the ones that appear only once…"New to the CLI? Get gizza →
Open it by URL
Pre-fill and auto-run this tool with query parameters — the names match the API/CLI:
https://gizza.ai/tools/find-unique-lines/?text=Paste%20lines%20to%20find%20the%20ones%20that%20appear%20only%20once%E2%80%A6&ignore_case=true&trim=trueMachine-readable descriptor: tool.json — title + parameters JSON Schema for agents.