CISO Tribune

Vendor comparison · 2 companies

Prompt Security vs WitnessAI

Prompt Security offers protection for both employee use of AI tools and the apps an organization builds. WitnessAI sells an AI security and governance platform that brings humans and agents under one platform. CISO Tribune files both under AI firewalls and guardrails and Workforce AI usage security. This page sets the two records side by side: what each sells, where it is based, who owns and funds it, the customers it names and its recent news, each fact numbered to its source.

Change the companies

Up to four companies side by side.

  • Prompt Security
  • WitnessAI
Prompt Security vs WitnessAI: Products, Customers and Funding Compared
Prompt SecurityPrompt Security offers protection for both employee use of AI tools and the apps an organization builds.prompt.securityWitnessAIWitnessAI sells an AI security and governance platform that brings humans and agents under one platform.witness.ai
What it sells
  • Prompt Fuzzer[4]An open source tool for AI vulnerability assessment.
  • Observe[6][11]Finds and catalogs AI applications, agents and MCP servers, and visualizes AI conversations and agentic activity.
  • Control[1][5][6][7][10][11]Governs what AI agents and employees can do, routes prompts to models based on risk or purpose, and generates audit trails.
  • Protect[1][5][6][8][11]Applies runtime security controls and content guardrails intended to block prompt injection and jailbreak attempts and filter harmful responses.
Categories
Headquarters
Not stated on its pagesMountain View, United States[4]
Founded
2023[1]2023[3]
Ownership and funding
Owned by SentinelOne since 2025[3][7][8][10]Privately held[2][13]
Named customers
Not stated on its pagesNot stated on its pages
Recent news
Not stated on its pagesNot stated on its pages
G2 and Gartner Peer Insights
  • G2: listed, seen November 10, 2026[10]
  • Gartner Peer Insights: Not stated on its pages
  • G2: listed, seen November 10, 2026[13]
  • Gartner Peer Insights: Not stated on its pages
Who it fits
Not written yetFrom its own pages, the company sells mainly to enterprises, saying they need security and governance that extends from humans to agents. It addresses employee use of AI, citing risks around sensitive data, compliance, and shadow AI. It also addresses AI agents, which it describes as connecting to tools, accessing data, and taking actions on behalf of employees.
Last verified
September 27, 2026November 2, 2026

Where they overlap

  • Prompt Security and WitnessAI are both filed under AI firewalls and guardrails and Workforce AI usage security.
  • Both were founded in 2023.

Where they differ, field by field

  • Prompt Security's primary category is AI firewalls and guardrails; WitnessAI's is Workforce AI usage security.
  • Prompt Security is also filed under AI model and agent security. WitnessAI is also filed under AI governance.
  • Prompt Security lists Prompt Fuzzer. WitnessAI lists Observe, Control and Protect.
  • WitnessAI is headquartered in Mountain View, United States.
  • Prompt Security is owned by SentinelOne, since 2025. WitnessAI is privately held.

What it sells: Prompt Security

What Prompt Fuzzer does[4]
Prompt Fuzzer is listed under AI Security Tools on the Prompt Security site. The site describes it as an open source tool for AI vulnerability assessment.

Questions about Prompt Security and WitnessAI

What do Prompt Security and WitnessAI sell?
Prompt Security sells Prompt Fuzzer. WitnessAI sells Observe, Control and Protect.
Are Prompt Security and WitnessAI in the same category?
They share AI firewalls and guardrails and Workforce AI usage security. Prompt Security's primary category is AI firewalls and guardrails and WitnessAI's is Workforce AI usage security.
Where are Prompt Security and WitnessAI headquartered?
WitnessAI is headquartered in Mountain View, United States.
When were Prompt Security and WitnessAI founded?
Both were founded in 2023.
Who owns Prompt Security and WitnessAI?
Prompt Security is owned by SentinelOne, since 2025. WitnessAI is privately held.
Who are Prompt Security and WitnessAI sold to?
From its own pages, the company sells mainly to enterprises, saying they need security and governance that extends from humans to agents.

About Prompt Security

Prompt Security offers protection for both employee use of AI tools and the apps an organization builds. Prompt Security continuously tracks prompts per day in organizations of 500 to 1,000 employees.[4][5]

Prompt Security holds that securing agentic AI is fundamentally different from securing traditional software. Prompt Security states that agents act autonomously, call tools and reason over untrusted input, so prompt injection, identity and runtime behavior have to be governed in real time and not only at the perimeter.

Prompt Security provides a security skill suite for OpenClaw, NanoClaw and Hermes agents.[6]

Prompt Security provides a tool that tracks and analyzes OpenClaw deployments across an organization. Prompt Security provides a tool that tests and hardens a system prompt against dynamic LLM-based attacks.[4][9]

Prompt Security publishes news, research, tools and analysis for security teams responding to AI threats. Prompt Security describes an AI gateway as a centralized layer between an organization's users or applications and the AI models or services they call. An AI gateway, as Prompt Security describes it, lets security teams monitor, control and secure that traffic from one place instead of instrumenting every application separately.[4]

Prompt Security curates an interactive, continuously updated directory of 471 companies building security for agentic AI, organized across 14 functional categories. Both pure-play startups and dedicated AI-security lines from larger vendors are in scope for the Prompt Security directory. Entries in the Prompt Security directory are compiled from vendor websites, product documentation, funding announcements, public company registries and analyst coverage. Placement in the Prompt Security directory reflects publicly stated capabilities, not vendor marketing tiers. Category definitions and threat coverage in the Prompt Security directory are mapped against established, independent frameworks for AI and LLM security. The full dataset behind the Prompt Security directory is open and machine-readable.[2][4][5][6][9]

Prompt Security on the record

Sources

Prompt Security full record

  1. [1]Prompt security partners with f5 to secure genai applications with a firewall for ai 302131373Prompt Security via PR Newswire · prnewswire.com · published April 30, 2024 · Tier A
  2. [2]Securing ai promptSentinelOne · sentinelone.com · undated page, accessed September 27, 2026 · Tier A
  3. [3]Sentinelone completes acquisition of prompt securitySentinelOne via The Globe and Mail · theglobeandmail.com · published September 5, 2025 · Tier A
  4. [4]Prompt Security | From SentinelOnePrompt Security · undated page, accessed October 27, 2026 · Tier A
  5. [5]AI Security | AI Glossary | Prompt SecurityPrompt Security · undated page, accessed October 27, 2026 · Tier A
  6. [6]ClawSec: A Security Skill Suite for OpenClaw AgentsPrompt Security · undated page, accessed October 27, 2026 · Tier A
  7. [7]AI Security Startups Map — Agentic AI Vendors by CategoryPrompt Security · undated page, accessed October 27, 2026 · Tier A
  8. [8]About this Map & Methodology — AI Security Startups MapPrompt Security · undated page, accessed October 27, 2026 · Tier A
  9. [9]OneClaw DashboardPrompt Security · undated page, accessed November 10, 2026 · Tier A
  10. [10]Prompt Security Pros and Cons | User Likes & DislikesG2 · undated page, accessed November 10, 2026 · Tier C

WitnessAI full record

  1. [1]Unified AI Security and Governance Platform | WitnessAIWitnessAI · undated page, accessed September 27, 2026 · Tier A
  2. [2]Witnessai raises 58 million for global expansion and announces new ways to secure ai agents 302659319WitnessAI via PR Newswire · prnewswire.com · published January 13, 2026 · Tier A
  3. [3]Witnessai launches with guardrails for aiDark Reading · darkreading.com · published May 21, 2024 · Tier B
  4. [4]WitnessaiAppSec Santa · appsecsanta.com · published April 3, 2026 · Tier C
  5. [5]Scaling AI Security with WitnessAI - WitnessAIWitnessAI · undated page, accessed November 10, 2026 · Tier A
  6. [6]AI Security Platform | Enterprise AI Governance | WitnessAIWitnessAI · undated page, accessed November 10, 2026 · Tier A
  7. [7]WitnessAI 2.0 Delivers New Regulatory Compliance Capabilities to Support Safe AI Adoption - WitnessAIWitnessAI · published April 30, 2025 · Tier A
  8. [8]Ensuring Compliance with the EU AI Act - WitnessAIWitnessAI · undated page, accessed November 10, 2026 · Tier A
  9. [9]WitnessAI Achieves SOC 2 Type II Compliance - WitnessAIWitnessAI · published October 21, 2025 · Tier A
  10. [10]WitnessAI Joins ServiceNow Control Tower Alliance - WitnessAIWitnessAI · undated page, accessed November 10, 2026 · Tier A
  11. [11]TENEX.AI and WitnessAI Partner to Deliver Managed Security and Compliance Services for Enterprise AI - WitnessAIWitnessAI · published June 17, 2025 · Tier A
  12. [12]How Security Leaders Prove ROI and Reduce Risk - WitnessAIWitnessAI · undated page, accessed November 10, 2026 · Tier A
  13. [13]WitnessAI Reviews 2026: Details, Pricing, & FeaturesG2 · undated page, accessed November 10, 2026 · Tier C

Spot a factual error? Request a correction.