Bash Checker — Free Online
Bash Checker is a free browser-based tool that reviews any Bash script for syntax errors, unsafe patterns, and 12 dimensions of code quality — without ever executing the script.
Example: unsafe rm the checker catches
#!/bin/bash
# rm with an unquoted variable — deletes the wrong file if $target has spaces
target=$1
rm -rf $target/*
What the bash checker inspects
The checker scans your script for parse errors, unquoted expansions, missing shebangs, brittle globbing, command injection risk, missing set -euo pipefail, and dozens of other ShellCheck-style issues. Every finding is line-anchored with a severity label so you can triage instantly.
How it differs from `bash -n`
`bash -n` only checks parseability — it misses semantic bugs. This checker layers static semantic analysis on top: it flags quoting issues that will silently corrupt data at runtime, subshell traps that never fire, and race conditions in file operations.
When to use it
Reviewing a script pasted from a gist, auditing a shell installer before running curl | bash, or catching regressions before pushing to CI. No install step means you can check untrusted scripts from a locked-down machine.
Frequently asked questions
- Does the bash checker execute my script?
- No. The script is treated as text and analyzed statically. Nothing runs.
- Do I need to install anything?
- No. It runs in your browser session. Nothing to install, no accounts, no cost.
- What Bash versions are supported?
- Bash 3.2 through 5.x. The checker also flags Bash-only constructs when a POSIX sh shebang is declared.