Calculator
What the Remove Duplicate Lines does
Remove Duplicate Lines: calculates Lines kept, Lines removed and Output from Lines, Ignore case when comparing and Ignore leading and trailing spaces. Example: ignore case when comparing No, ignore leading and trailing spaces Yes and remove blank lines Yes gives lines kept 7.
Point it at Lines, Ignore case when comparing, Ignore leading and trailing spaces and Remove blank lines and it returns Lines kept, Lines removed and Output. Edit a field and the answer updates in place.
Typical users are people preparing copy for publishing. Doing this by hand is tedious and error-prone once the text runs past a few lines.
There is no account, no upload and no server round trip, because the page does the work itself.
The sections that follow cover the fields, the method, and one full example computed from the defaults.
What do the Remove Duplicate Lines fields mean?
The Remove Duplicate Lines uses 5 inputs. Each input has a default that makes sense on its own, so a partial edit still gives a valid result.
| Field | What to enter | Default |
|---|---|---|
| Lines | paste or type any amount of text | banana apple Cherry apple banana date fig 10 plums 2 plums |
| Ignore case when comparing | choose from Yes or No | No |
| Ignore leading and trailing spaces | choose from Yes or No | Yes |
| Remove blank lines | choose from Yes or No | Yes |
| Keep | choose from First occurrence, Last occurrence, Only lines that appear once or Only the duplicated lines | First occurrence |
How does the Remove Duplicate Lines work?
Each output is derived from the inputs above in a single pass; there is no hidden state carried between runs, so the same inputs always give the same calculation.
Nothing is computed until the inputs pass their checks, so you will not get a confident answer built on a typo.
Worked example
These are the values the Remove Duplicate Lines loads by default, and the result it produces from them. Here is the calculation as it stands the moment the page loads.
| Lines | banana apple Cherry apple banana date fig 10 plums 2… |
|---|---|
| Ignore case when comparing | No |
| Ignore leading and trailing spaces | Yes |
| Remove blank lines | Yes |
| Keep | First occurrence |
| Lines kept | 7 |
|---|---|
| Lines removed | 3 |
| Output | banana apple Cherry date fig 10 plums 2 plums |
How to use it
- Paste your content into Lines.
- Pick a value for Ignore case when comparing: the options are Yes or No.
- Pick a value for Ignore leading and trailing spaces: the options are Yes or No.
- Pick a value for Remove blank lines: the options are Yes or No.
- Pick a value for Keep: the options are First occurrence, Last occurrence, Only lines that appear once or Only the duplicated lines.
- Each keystroke triggers a fresh calculation, which is cheap because it happens locally.
- You get Lines kept, Lines removed and Output back.
- Copy Link is the quickest way to send the exact scenario to someone else.
What this tool does not do
- Very large pastes are limited by your browser memory rather than a server quota.
- Word and character definitions vary between tools: this one counts whitespace-separated tokens.
- There is no audit trail: if you need one, record the inputs alongside the output.
Frequently asked questions
Just Lines, Ignore case when comparing, Ignore leading and trailing spaces, Remove blank lines and Keep. Nothing starts empty, which makes it easy to isolate the effect of a single variable.
With the values loaded when the page opens, lines kept comes out as 7. Any edit re-runs the calculation, so there is no stale number on screen.
Nothing leaves your machine. The only network traffic is loading the page itself.
Nothing at all. There is no registration, no paywall and no per-use quota.
The output is deterministic. The same inputs always give the same answer, and the method is documented above so you can check it.