Shellcheck Paste Analyzer

Paste a Bash or Zsh script snippet to get instant warnings, suggestions, and best-practice recommendations — all processed locally in your browser.

Script

The analysis updates as you type.

Examples:

How It Works

This tool performs static analysis on your shell script by checking for common pitfalls and anti-patterns:

Quoting issues — unquoted variables that may cause word splitting or globbing
Deprecated syntax — backtick command substitution, legacy test brackets, and more
Useless constructs — unnecessary cat, echo, or eval usage
Best practices — missing shebangs, unused variables, unsafe cd without error checking
Portability — Bash-specific features used without a proper shebang

All processing happens locally in your browser — no data is sent to any server. For comprehensive analysis, consider using the full ShellCheck tool.

Common Shell Script Issues

Issue	Bad	Good
Unquoted variable	`echo $foo`	`echo "$foo"`
Backtick substitution	x=`cmd`	`x=$(cmd)`
Legacy test	`[ $a == $b ]`	`[[ $a == "$b" ]]`
Useless cat	`cat file \| grep x`	`grep x file`
Unsafe cd	`cd /dir; rm *`	`cd /dir \|\| exit; rm *`
Implicit split	`for f in $(ls)`	`for f in *`

Embed This Util

You can embed this util on your own site as a widget. Adding ?embed=1 to the URL loads a compact version with just the tool itself; no header, menu, or documentation. Paste this snippet into your HTML:

Copy snippet Adjust the height to taste.

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