tail command: show the end of a file
tail prints just the end of a file. Learn the default of ten lines, how to set the count with -n, and how -f follows a log as it is written, by running the commands in a real terminal in your browser.
Updated: 2026-09-05
Syntax
tail [options] file...Prints the end of a file. Without a count, that means ten lines.
Try it first
The terminal on this page has a log file with 30 lines in it.
$ tail logs/app.log
line 21
line 22
line 23
line 24
line 25
line 26
line 27
line 28
line 29
line 30The last ten lines. This is the useful end of a log, because new lines are appended at the bottom.
Choosing how many lines
-n takes the count.
$ tail -n 3 logs/app.log
line 28
line 29
line 30Right after something breaks, this is the first thing to look at.
Counting from the start instead
Put a + in front of the number and the meaning flips.
It is no longer a count from the end, it is from that line onwards.
$ tail -n +28 logs/app.log
line 28
line 29
line 30Following a live log
-f keeps the file open and prints new lines as they arrive.
tail -f app.logThis is the standard way to watch a running server. Press Ctrl+C to stop.
When you actually reach for it
tail is how you watch what is happening now.
| Situation | What you type |
|---|---|
| See the error that just happened | tail -n 50 app.log |
| Follow a running log | tail -f app.log |
| Follow only the errors | tail -f app.log | grep ERROR |
| Skip a header row | tail -n +2 users.csv |
Things that trip people up
-f waits for you to stop it.
It never returns to the prompt on its own.
Ctrl+C ends it.
Short files come out whole.
$ tail -n 2 notes.txt
buy milk
call the bankIf the file has fewer than ten lines, tail and cat show you the same thing.
A file being written can look cut off at the end. You are reading a line that is not finished yet; wait a moment and the rest appears.
Practise it hands-on
webterm.appthis site
- Try the tutorial
Advanced Terminal Commands
Learn commands for specific situations
learn.webterm.appa separate site
WebTerm Learn: from one command to actually using it
Commands stick when they show up in a real sequence of work, not one at a time. There is a course that builds them up in order.
See the courseRelated commands
Frequently asked questions
- How many lines does tail print?
- Ten by default. Use -n to ask for a different number.
- What does tail -f do?
- It keeps the file open and prints new lines as they are written, which is how people watch a running server's log. Press Ctrl+C to stop.
- Why is tail the tool for logs?
- Logs grow downwards, so what is happening right now is at the end. The beginning is startup noise that rarely helps during an incident.
- Can I count from the start instead?
- Yes. -n +28 means from line 28 to the end, counted from the beginning rather than the end.
- How is it different from head?
- head takes the beginning, tail the end. The options are the same, so learning one gives you the other.