Best Free AI & LLM Security Tools

For most teams the fastest free wins are a threat model and a configuration review. On PlayCISO the free, browser-based set covers that end to end: the LLM Threat Model maps a nine-question intake to the OWASP LLM Top 10; LLM Security (OWASP) walks each risk with defences; the MCP Security Linter gives a static review of a pasted Model Context Protocol config with no SSRF; Agent Builder + Red-Team lets you build a small LLM pipeline and attack it; the In-Browser LLM Sandbox runs a small open-weights model with no key and nothing uploaded; and the Embeddings Explorer shows how text clusters live. All of these need no signup. Deeper tools — the AI Threat Model Builder, RAG & Vector DB Hardening, the AIBOM suite and the governance pack — are part of PlayCISO Pro.

The OWASP Top 10 for Large Language Model Applications is a community-maintained list of the most critical security risks specific to LLM-powered systems — prompt injection, insecure output handling, training-data poisoning, model denial of service, supply-chain vulnerabilities, sensitive-information disclosure, insecure plugin and tool design, excessive agency, overreliance, and model theft. PlayCISO’s free LLM Threat Model maps a nine-question intake directly to this list, and LLM Security (OWASP) explains each risk with concrete defences.

An AI Bill of Materials (AIBOM) is a machine-readable inventory of everything in an AI system — the models (base and fine-tunes), the training and evaluation datasets, the AI/ML code dependencies, the runtime configuration, and risk and assurance metadata — each with its own version, license and provenance. It extends a traditional SBOM, which only inventories code, to the model and data components an SBOM never described. PlayCISO produces AIBOMs in CycloneDX ML-BOM form and converts to or from the SPDX 3.0 AI Profile; those generation and validation tools are part of PlayCISO Pro, while the AIBOM vs SBOM explainer gives the free background.

The Model Context Protocol (MCP) lets an AI assistant reach external tools and data through MCP servers, so an untrusted or misconfigured server can expose your environment to prompt injection, data exfiltration or command execution. Start by treating every server as untrusted: review its manifest and permissions, grant the least tool access it needs, require human approval for sensitive actions, sandbox it, and log what it does. PlayCISO’s free MCP Security Linter gives a static review of a pasted MCP config or manifest with no SSRF; the Pro Malicious MCP Scanner checks servers against known-bad patterns, and MCP Server Risk helps you decide whether a given server should be allowed, and under what controls.

The ones labelled Free on this page run entirely in your browser with no signup and nothing uploaded — the LLM and agent threat modelers, the MCP linter, the LLM sandbox, the embeddings explorer, the LiteLLM supply-chain checker, the abliterated-models explainer and the AI Adoption Hub. The tools labelled Pro (the AI Threat Model Builder, RAG hardening, the full AIBOM suite, the governance pack, the footprint scanner and others) are part of PlayCISO Pro, which starts at $5 alongside a large free tier. Every card below is labelled honestly so you know before you click.