PREFLIGHT / BEFORE & AFTER
What changed
beyond the code?
See which types of warning signs appear or disappear when code changes. Paste the old version in Before and the new version in After, select their language, then click Compare capabilities. Neither version runs or leaves your browser.
Load example replaces both inputs after confirmation. Keep a copy of important drafts before leaving this page.
Paste both versions or load an example.
These are text-pattern checks, not a complete security review. Harmless comments can trigger warnings, and real risks can be missed. A warning disappearing does not prove the risk is gone. A warning in both versions does not mean the behavior or risk stayed the same. Results group possible actions, such as changing files. They do not explain every code change. Line numbers start at 1 and refer to the named version.
Reports include a digital fingerprint (SHA-256 hash) of each code version, warning signs, line numbers and the limits of the check—not the code itself. Hashes identify editor text, not proof of safety or authorship. Reports still reveal capability metadata; review before sharing.
No persistence, uploads, execution, or policy enforcement. Each input is limited to one million characters. Browser extensions and device access are outside this guarantee. Avoid secrets.