Custom GPT Vulnerability Tester
Find jailbreak vulnerabilities, data leak risks, and prompt injection holes in your Custom GPT — with test prompts and a hardened system prompt rewrite.
Ethical testing only
Only test Custom GPTs you own or have explicit permission to analyze. Never use these techniques maliciously against others' systems.
Frequently asked questions
What vulnerabilities does this tool check for?+
It analyzes your Custom GPT system prompt for common weaknesses: system prompt leakage, uploaded file and knowledge-base exposure, tool/API misuse, and susceptibility to jailbreaks and prompt injection. You get an overall risk score, a breakdown per exposure type, and specific mitigations for each finding.
Does it actually attack my live GPT?+
No. The tool performs a static analysis of the system prompt text you paste — it never connects to or probes your published GPT. It generates recommended test prompts that you run against your GPT yourself, along with the expected secure behavior and red-flag responses to watch for.
Is my system prompt sent to a server?+
Yes. The prompt is sent to our server, where an AI model performs the security analysis. Before pasting, remove any real secrets such as API keys, passwords, or private URLs — the analysis only needs the instructions themselves, not live credentials.
How do I use the recommended test prompts?+
Open a fresh conversation with your Custom GPT and paste each test prompt. Compare the response against the listed expected secure behavior. If the reply matches any of the red-flag responses — for example, revealing instructions or file contents — apply the corresponding hardening recommendation and re-test.
Can a system prompt ever be fully jailbreak-proof?+
No. Any instructions or files a model can access can potentially be extracted by a determined attacker, and new jailbreak techniques appear constantly. Hardening meaningfully raises the effort required, but you should never place truly sensitive data (credentials, private customer data) in a Custom GPT’s instructions or knowledge files.
Is this tool free?+
Yes. The vulnerability analysis, test prompts, and hardened system prompt template are all free, with no account required.