Powerlevel10k

Powerlevel10k is a theme for ZSH. It's a backward-compatible fork of Powerlevel9k with lower latency and better prompt responsiveness.

If you like the looks of Powerlevel9k but feeling frustrated by its slow prompt, simply replace your powerlevel9k theme with powerlevel10k and enjoy responsive shell like it's 80's again!

Powerlevel10k uses the same configuration options as Powerlevel9k and produces the same results. It's simply faster. There is no catch.

Table of Contents

1. Installation and configuration
   1. Manual installation
   2. Extra configuration
2. Try it out
   1. For Powerlevel9k users
   2. For new users
   3. Docker playground
3. How fast is it?
4. What's the catch?

Installation and configuration

For installation and configuration instructions see Powerlevel9k. Everything in there applies to Powerlevel10k as well. Follow the official installation guide, make sure everything works and you like the way prompt looks. Then simply replace Powerlevel9k with Powerlevel10k. Once you restart zsh, your prompt will be faster. No configuration changes are needed.

Manual installation

git clone https://github.com/romkatv/powerlevel10k.git ~/powerlevel10k
echo 'source ~/powerlevel10k/powerlevel10k.zsh-theme' >>! ~/.zshrc

Make sure to disable your current theme.

Extra configuration

Powerlevel10k has a handful of configuration options that Powerlevel9k doesn't have. They are still using the POWERLEVEL9K prefix though.

• POWERLEVEL9K_VCS_MAX_SYNC_LATENCY_SECONDS (FLOAT) [default=0.05]

  If it takes longer than this to fetch git repo status, display the prompt with a greyed out vcs segment and fix it asynchronously when the results come it.

• POWERLEVEL9K_VCS_BACKENDS (ARRAY) [default=(git)]

  The list of VCS backends to use. Supported values are git, svn and hg. Note that adding anything other than git will make prompt slower even when your current directory isn't a repo.

• POWERLEVEL9K_GITSTATUS_DIR (STRING) [default=$POWERLEVEL9K_INSTALLATION_DIR/gitstatus]

  Directory with gitstatus plugin. By default uses a copy bundled with Powerlevel10k.

• POWERLEVEL9K_DISABLE_GITSTATUS (STRING) [default="false"]

  If set to "true", Powerlevel10k won't use its fast git backend and will fall back to vcs_info like Powerlevel9k.

• POWERLEVEL9K_MAX_CACHE_SIZE (INT) [default=10000]

  The maximum number of elements that can be stored in the cache. When the cache grows over this limit, it gets cleared.

• POWERLEVEL9K_VCS_MAX_INDEX_SIZE_DIRTY (INT) [default=-1]

  Don't scan for dirty files in git repos with more files in the index than this. Instead, show them with the "dirty" color (yellow by default) whether they are dirty or not. This makes git prompt much faster on huge repositories.

Try it out

Try Powerlevel10k without making any changes to your setup. If you like it, see Installation and configuration for how to make a permanent switch.

For Powerlevel9k users

If you are currently using Powerlevel9k, you can try Powerlevel10k in a temporary zsh shell. The prompt will look exactly like what you are used to but it'll be faster.

git clone https://github.com/romkatv/powerlevel10k.git /tmp/powerlevel10k
source /tmp/powerlevel10k/powerlevel10k.zsh-theme

When you are done playing, rm -rf /tmp/powerlevel10k and exit zsh.

For new users

git clone https://github.com/romkatv/powerlevel10k.git /tmp/powerlevel10k
echo "
  # Your prompt configuration goes here.
  POWERLEVEL9K_PROMPT_ON_NEWLINE=true
  POWERLEVEL9K_LEFT_PROMPT_ELEMENTS=(root_indicator dir_writable dir vcs)
  POWERLEVEL9K_RIGHT_PROMPT_ELEMENTS=(status command_execution_time background_jobs time)
  source /tmp/powerlevel10k/powerlevel10k.zsh-theme" >/tmp/powerlevel10k/.zshrc
ZDOTDIR=/tmp/powerlevel10k zsh

When you are done playing, rm -rf /tmp/powerlevel10k and exit zsh.

Docker playground

You can try Powerlevel10k in Docker (Linux only). Once you exit zsh, the image is deleted.

docker run -e LANG=C.UTF-8 -e LC_ALL=C.UTF-8 -e TERM=$TERM -it --rm ubuntu bash -c '
  set -uex
  apt update
  apt install -y zsh git
  cd
  git clone https://github.com/romkatv/powerlevel10k.git
  echo "
    # Your prompt configuration goes here.
    POWERLEVEL9K_PROMPT_ON_NEWLINE=true
    POWERLEVEL9K_LEFT_PROMPT_ELEMENTS=(root_indicator dir_writable dir vcs)
    POWERLEVEL9K_RIGHT_PROMPT_ELEMENTS=(status command_execution_time background_jobs time)
    source ~/powerlevel10k/powerlevel10k.zsh-theme" >~/.zshrc
  cd powerlevel10k
  zsh -i'

How fast is it?

Powerlevel10k renders prompt about 50 times faster than powerlevel9k/master (stable version) and about 15 times faster than powerlevel9k/next (beta version).

Here are benchmark results obtained with zsh-prompt-benchmark on Intel i9-7900X running Ubuntu 18.04.

Theme	/	~/nerd-fonts
powerlevel9k/master	135 ms	233 ms
powerlevel9k/next	27 ms	107 ms
powerlevel10k	2 ms	6 ms
naked zsh	1 ms	1 ms

Columns define the current directory where the prompt was rendered.

• / -- root directory, not a git repo.
• ~/nerd-fonts -- nerd-fonts git repo with 4k files.

Here's how the prompt looked like during benchmarking.

It was identical in Powerlevel10k and Powerlevel9k. Even though Powerlevel10k can dynamically switch to async prompts, it wasn't happening here because latencies were low. Prompts with both themes were essentially synchronous with every prompt having up-to-date git info.

This table used to have another column for Linux kernel git repo, which is massive. It's been removed because it's not a fair comparison. Powerlevel10k automatically detects that fetching git status is slow and switches to async prompt generation, which allows it to achieve 2 ms prompt latency but not all its prompt have up-to-date git info. Those that don't, have vcs segment greyed out.

Configuration that was used:

POWERLEVEL9K_LEFT_PROMPT_ELEMENTS=(dir_writable dir vcs)
POWERLEVEL9K_RIGHT_PROMPT_ELEMENTS=(status background_jobs time custom_rprompt)

POWERLEVEL9K_MODE=nerdfont-complete
POWERLEVEL9K_PROMPT_ON_NEWLINE=true
POWERLEVEL9K_CUSTOM_RPROMPT=custom_rprompt
POWERLEVEL9K_ROOT_ICON=\\uF09CPOWERLEVEL9K_TIME_ICON=\\uF017
POWERLEVEL9K_CUSTOM_RPROMPT_ICON=\\uF005
POWERLEVEL9K_TIME_BACKGROUND=magenta
POWERLEVEL9K_CUSTOM_RPROMPT_BACKGROUND=blue
POWERLEVEL9K_STATUS_OK_BACKGROUND=grey53
POWERLEVEL9K_BACKGROUND_JOBS_BACKGROUND=orange1
POWERLEVEL9K_BACKGROUND_JOBS_FOREGROUND=black

function custom_rprompt() echo -E "hello world"

sleep 86400 &  # spawn two background jobs
sleep 86400 &

Here's the same benchmark for Windows Subsystem for Linux (WSL) with zsh running in the standard Command Prompt (cmd.exe).

Theme	/	~/nerd-fonts
powerlevel9k/master	313 ms	693 ms
powerlevel9k/next	119 ms	442 ms
powerlevel10k	16 ms	19 ms
naked zsh	16 ms	16 ms

The fastests results are probably limited by the key repeat rate.

Here's Raspberry Pie 3. I replaced nerd-fonts repo with git in this benchmark becase the former didn't fit on my SD card. Git repo had 3.6k files, so about the same size. I set POWERLEVEL9K_VCS_MAX_SYNC_LATENCY_SECONDS=1 to prevent Powerlevel10k from switching to async prompts. The default threshold is 0.05, or 50 ms, after which Powerlevel10k will go async (git latency in ~/git was close to 100 ms, so above the default 50 ms). Naturally, async is a good thing, so you shouldn't disable it in your configs. I only did it to measure sync latency.

Theme	/	~/git
powerlevel9k/master	312 ms	584 ms
powerlevel10k	15 ms	108 ms
naked zsh	1 ms	1 ms

The next branch of Powerlevel9k didn't work on Raspberry Pie, so I couldn't benchmark it.

What's the catch?

Really, there is no catch. It's literally the same prompt with the same flexibility configuration format as Powerlevel9k. But much faster.

If you really need to know, here's where Powerlevel10k differs from Powerlevel9k:

• Git prompt doesn't show tags and revisions. Open an issue if you need them.
• By default only git vcs backend is enabled. If you need svn and hg, you'll need to set POWERLEVEL9K_VCS_BACKENDS. See Extra configuration.
• Fewer configuration options can be changed after the theme is loaded. For example, if you decide to change background color of some segment in the middle of an interactive session, it may not work.

Known bugs

When a notification about an exiting job is displayed, prompt content doesn't get refreshed. In Powerlevel9k it does. This could be fixed but the fix will add non-trivial complexity and extra prompt latency.