$ wc -l data.txt
18408096 data.txt

$ hyperfine 'sort -u data.txt | wc -l' 'uc -np data.txt'
Benchmark 1: sort -u data.txt | wc -l
  Time (mean ± σ):     16.030 s ±  0.181 s    [User: 86.713 s, System: 1.165 s]
  Range (min … max):   15.699 s … 16.324 s    10 runs

Benchmark 2: uc -np data.txt
  Time (mean ± σ):      2.889 s ±  0.101 s    [User: 2.435 s, System: 0.454 s]
  Range (min … max):    2.721 s …  3.065 s    10 runs

Summary
  uc -np data.txt ran
    5.55 ± 0.20 times faster than sort -u data.txt | wc -l

go install github.com/essentialkaos/uc@latest

Usage: uc {options} file

Options

  --dist, -d format     Show number of occurrences for every line (-/simple/table/json)
  --max, -m num         Max number of unique lines
  --no-progress, -np    Disable progress output
  --no-color, -nc       Disable colors in output
  --help, -h            Show this help message
  --version, -v         Show version

Examples

  uc file.txt
  Count unique lines in file.txt

  uc -d file.txt
  Show distribution for file.txt

  uc --dist=table file.txt
  Show distribution as a table for file.txt

  uc -d -m 5k file.txt
  Show distribution for file.txt with 5,000 uniq lines max

  cat file.txt | uc
  Count unique lines in stdin data

  uc -m 100 < file.txt
  Count unique lines in stdin data with 100 uniq lines max