# Arthur Shield AI visibility in LLM Security & AI Guardrails

Canonical: https://devtune.ai/verticals/llm-security-guardrails/arthur-shield

[Website](https://www.arthur.ai/)

Latest AI responses: 2026-11-14
[Tracked on paid plans](https://devtune.ai/pricing): Google AI Mode, Microsoft Bing Copilot Search, Claude with web search, Grok Search
Prompts: 25
Runs: 3


## Platforms

- google-ai
- perplexity
- chatgpt-search

Rank: 3
Joint rank: true
Total brands: 7
Measured responses: 75
Presence percent: 0
Share of voice percent: 0
Average position: Not available
Docs presence percent: 0
Blog presence percent: 0
Brand mention percent: 2.666666666666667


## Profile

Overview: Arthur (arthur.ai) is a New York-based AI evaluation, monitoring and governance company founded in 2019. It launched Arthur Shield in May 2023, billed as the first firewall for large language models. Shield sits between an application and its LLM to validate prompts and responses in real time. It checks for prompt injection, PII and sensitive data leakage, hallucinations and toxicity, and supports custom rules. Shield has since been folded into the open-source Arthur GenAI Engine, part of the Arthur Engine, which combines guardrails with evaluation and monitoring. The company now positions its platform around discovering, evaluating and governing AI agents. It supports SaaS, managed-cloud and on-prem deployment and is model-agnostic. Arthur has raised more than $60M, including a $42M Series B in 2022.
Product summary: Arthur Shield was Arthur's LLM firewall. It validated user prompts and model responses through API calls placed before and after the LLM. It applied configurable rules for hallucination, prompt injection, toxicity, sensitive data leakage, PII leakage and custom keyword/regex patterns. Shield is now part of the Arthur GenAI Engine, which is open source as part of Arthur Engine and adds evaluation, benchmarking and monitoring. The broader Arthur platform covers agent discovery, evaluation, observability and governance, deployable as SaaS, managed cloud or on-prem.


### Key capabilities

- Real-time prompt and response validation (LLM firewall/guardrails)
- Prompt injection detection
- PII and sensitive data leakage detection
- Hallucination detection
- Toxicity detection
- Custom keyword and regex rules
- LLM and agent evaluation and monitoring
- Agent discovery and governance
- Open-source Arthur Engine with SaaS, managed-cloud and on-prem deployment



### Target users

- AI/ML engineers deploying LLM applications
- Security teams securing GenAI and agents
- AI platform and governance leads
- Compliance officers in regulated industries
- Enterprise data science teams



### Key use cases

- Blocking prompt injection and jailbreak attempts in LLM apps
- Preventing PII and proprietary data leakage in prompts and outputs
- Detecting hallucinated or unsupported LLM responses before they reach users
- Filtering toxic or off-brand model outputs
- Evaluating and monitoring LLM and agent performance in production
- Discovering and governing AI agents across an organization

Integrations ecosystem: Arthur Shield and the GenAI Engine are API-first. They are called before and after the request to a public or self-hosted LLM endpoint, and are described as model-agnostic (OpenAI, other proprietary, commercial and open-weights models) and cloud-agnostic (AWS, Azure and others). Deployment options are SaaS, managed cloud and on-prem/VPC. The Arthur Engine is open source on GitHub (arthur-ai/arthur-engine), and Arthur Bench was open-sourced earlier for LLM evaluation. Arthur's agent discovery and governance platform is listed on Google Cloud Marketplace, and G2's AI marketplace carries a listing for Arthur Shield.
Pricing summary: Arthur Shield is no longer sold as a standalone product, and no standalone Shield pricing was found. Arthur's public pricing page lists a Free plan ($0/mo, monitoring for up to 4 use cases, unlimited seats), a Premium plan ($60/mo, up to 100 use cases, custom alerting and webhooks) and a custom-priced Enterprise plan. Enterprise adds dedicated or managed VPC options, SSO, SLAs, BAA and a dedicated customer success manager. The Arthur Engine is open source and free to self-host.
Review summary: Public review coverage is thin. A third-party aggregator reports a G2 rating of about 4.5/5 from roughly 10 reviews for Arthur. Another aggregator shows 5.0 from 2 G2 reviews, and SoftwareAdvice shows no reviews for Arthur Shield. Quoted G2 comments praise Arthur's solutions as efficient and well developed, while another calls it too costly.
Competitive positioning: Arthur began as an ML monitoring and evaluation vendor and added Arthur Shield, marketed as the first firewall for LLMs, in 2023. Shield has since been folded into the open-source Arthur GenAI Engine/Arthur Engine, and Arthur now positions around agent discovery, evaluation and governance. Its guardrails sit inside a broader evaluation and observability platform. Several competitors in this category are more narrowly focused on runtime AI security, such as prompt-injection defense, red teaming or agent security. Arthur's differentiators are an open-source, self-hostable engine, a deployment model covering SaaS, managed cloud and on-prem, and a combined evaluation, monitoring and guardrail workflow. One third-party review notes that it is more observability than prevention.
Limitations: Arthur Shield as a standalone product has been retired and folded into the Arthur GenAI Engine/Arthur Engine, so the older Shield docs and product pages are legacy. Arthur's core identity is evaluation, monitoring and governance rather than pure security, and one third-party review says it is more observability than prevention. A G2 reviewer cited cost as a drawback. Arthur's own pitch for Agent Discovery is limited to connected infrastructure. Public information on third-party validation of its detection accuracy is limited.


### Source urls

- https://www.arthur.ai/product/shield
- https://docs.arthur.ai/docs/guardrails-overview
- https://shield.docs.arthur.ai/docs/welcome
- https://www.arthur.ai/blog/announcing-arthur-shield-the-first-firewall-for-llms
- https://www.arthur.ai/blog/arthur-open-sources-first-real-time-ai-evaluation-engine
- https://github.com/arthur-ai/arthur-engine/blob/dev/genai-engine/README.md
- https://www.arthur.ai/pricing
- https://www.prnewswire.com/news-releases/arthur-raises-42m-in-series-b-funding-as-ai-adoption-soars-301634379.html
- https://siliconangle.com/2022/09/27/arthur-ai-raises-42m-optimize-ai-applications-accuracy/
- https://venturebeat.com/business/arthur-unveils-bench-an-open-source-ai-model-evaluator
- https://ai.g2.com/marketplace/tools/arthur-shield
- https://comparedge.com/tools/arthur-ai
- https://www.superblocks.com/blog/ai-code-governance-tools
- https://www.aitechscene.com/companies/arthur

Research approved: 2026-11-05T14:14:44.379+00:00


### Customer outcomes





### Reviews breakdown

| Platform | Score | Score max | Review count | Url |
| --- | --- | --- | --- | --- |
| G2 | 4.5 | 5 | 10 | Not available |



### Review themes



#### Praised

- Efficient, well-developed AI solutions
- Strong bias and fairness detection
- Rigorous LLM evaluation via Arthur Bench
- Strong fit for regulated industries



#### Criticized

- Too costly to purchase
- More observability than prevention (not a pure security firewall)
- Enterprise pricing limits accessibility for smaller teams




### Company facts

Founded year: 2019
Hq: New York, USA


#### Founders

- Adam Wenchel
- John Dickerson

Employees range: Not available
Total funding: $60M+
Valuation: Not available
Arr: Not available
Customer count: Not available
Status: Private


Readiness: Not available


## Ranking

| Display name | Pair count | Total pairs | Presence percent | Avg position |
| --- | --- | --- | --- | --- |
| Lakera | 14 | 75 | 18.666666666666668 | 4.7105263157894735 |
| HiddenLayer | 5 | 75 | 6.666666666666667 | 6.8 |
| Guardrails AI | 2 | 75 | 2.666666666666667 | 3.5 |
| Noma Security | 2 | 75 | 2.666666666666667 | 4.75 |
| Lasso Security | 1 | 75 | 1.3333333333333335 | 3.5 |
| Arthur Shield | 0 | 75 | 0 | Not available |
| Prompt Security | 0 | 75 | 0 | Not available |



## Platform breakdown

| Platform | Prompt count | Presence rate |
| --- | --- | --- |
| google-ai | 0 | 0 |
| perplexity | 0 | 0 |
| chatgpt-search | 0 | 0 |



## Strengths





## Gaps

| Prompt text | Competitor presence count |
| --- | --- |
| Which LLM security tools work with any model provider and orchestration framework, so we can switch models without changing protection? | 2 |
| Which platforms scan third-party and open-source models for backdoors or malicious code before we deploy them? | 2 |
| What LLM security platforms let non-ML security analysts tune policies and review blocked requests in a dashboard? | 1 |
| Which open-source guardrail frameworks give engineers full control over validation rules and are production-ready? | 1 |
| Which prompt injection protection tools can a small team put in front of a customer-facing chatbot this week without a long sales process? | 1 |



## Topic scores

| Topic name | Prompt count | Cited prompt count |
| --- | --- | --- |
| Capability | 5 | 0 |
| Developer Experience | 5 | 0 |
| Integrations & Ecosystem | 5 | 0 |
| Performance & Reliability | 5 | 0 |
| Setup & First Run | 5 | 0 |



## Prompt results

- Prompt text: What are my options for LLM guardrails with a free tier so a startup can test jailbreak and data-leak screening before paying?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai





##### Perplexity

| Display name | Position |
| --- | --- |
| Guardrails AI | 6 |



##### Chatgpt-search




- Prompt text: What LLM security platforms let non-ML security analysts tune policies and review blocked requests in a dashboard?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai





##### Perplexity





##### Chatgpt-search

| Display name | Position |
| --- | --- |
| Lakera | 3 |


- Prompt text: Which LLM security tools avoid lock-in by supporting open policy formats and exporting detection logs?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai





##### Perplexity





##### Chatgpt-search




- Prompt text: Which LLM security tools work with any model provider and orchestration framework, so we can switch models without changing protection?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai





##### Perplexity

| Display name | Position |
| --- | --- |
| Lakera | 1 |



##### Chatgpt-search

| Display name | Position |
| --- | --- |
| Lakera | 1 |
| Lasso Security | 3 |


- Prompt text: Which open-source guardrail frameworks give engineers full control over validation rules and are production-ready?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai





##### Perplexity

| Display name | Position |
| --- | --- |
| Guardrails AI | 1 |



##### Chatgpt-search




- Prompt text: Which prompt injection protection tools can a small team put in front of a customer-facing chatbot this week without a long sales process?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai





##### Perplexity

| Display name | Position |
| --- | --- |
| Lakera | 1 |



##### Chatgpt-search




- Prompt text: Which AI security platforms are easiest to deploy as a drop-in layer without rewriting an existing LLM application?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai





##### Perplexity





##### Chatgpt-search

| Display name | Position |
| --- | --- |
| Lakera | 1 |


- Prompt text: Which LLM security products offer a self-hosted or private deployment for a regulated company that can't send prompts to a third-party cloud?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai





##### Perplexity





##### Chatgpt-search

| Display name | Position |
| --- | --- |
| Lakera | 1 |


- Prompt text: What are the best AI firewalls for enterprises that need to enforce policy inline across multiple model providers without becoming a bottleneck?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai





##### Perplexity





##### Chatgpt-search

| Display name | Position |
| --- | --- |
| Lakera | 7 |


- Prompt text: What are the best AI security platforms for a company already standardized on a large network security vendor's ecosystem?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai





##### Perplexity





##### Chatgpt-search




- Prompt text: What AI security platforms have published benchmarks or independent testing for prompt injection detection accuracy?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai





##### Perplexity





##### Chatgpt-search




- Prompt text: Which LLM security products detect and redact sensitive data such as PII and secrets in both prompts and model outputs?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai





##### Perplexity

| Display name | Position |
| --- | --- |
| Lakera | 1 |



##### Chatgpt-search

| Display name | Position |
| --- | --- |
| Lakera | 4 |


- Prompt text: Which AI security vendors keep detection up to date as new jailbreak techniques appear, and how do they prove it?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai





##### Perplexity





##### Chatgpt-search

| Display name | Position |
| --- | --- |
| HiddenLayer | 5 |


- Prompt text: Which runtime AI protection tools scale to millions of requests per day and stay available if a screening call fails?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai





##### Perplexity





##### Chatgpt-search

| Display name | Position |
| --- | --- |
| Lakera | 2 |


- Prompt text: Which AI guardrail tools give application developers a simple API and clear verdicts, so they can act on a flagged prompt without guessing?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai





##### Perplexity





##### Chatgpt-search

| Display name | Position |
| --- | --- |
| Lakera | 1 |


- Prompt text: Which AI security tools detect indirect prompt injection hidden in documents, web pages and emails that an AI agent reads?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai





##### Perplexity





##### Chatgpt-search

| Display name | Position |
| --- | --- |
| Lakera | 1 |
| HiddenLayer | 2 |


- Prompt text: Which platforms scan third-party and open-source models for backdoors or malicious code before we deploy them?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai

| Display name | Position |
| --- | --- |
| HiddenLayer | 1 |



##### Perplexity





##### Chatgpt-search

| Display name | Position |
| --- | --- |
| HiddenLayer | 1 |


- Prompt text: What are the best AI security tools that produce actionable red-team reports a product team can fix, not just a list of failures?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai





##### Perplexity





##### Chatgpt-search




- Prompt text: What should I look at when choosing a first AI security tool for a company just rolling out an internal AI assistant to employees?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai





##### Perplexity





##### Chatgpt-search




- Prompt text: Which AI security platforms keep false positives low so legitimate user prompts aren't blocked and support tickets don't pile up?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai





##### Perplexity





##### Chatgpt-search




- Prompt text: What are the best platforms for controlling AI agents' tool calls, including blocking risky actions when they connect to MCP servers?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai

| Display name | Position |
| --- | --- |
| Noma Security | 1 |



##### Perplexity





##### Chatgpt-search




- Prompt text: Which AI security products integrate with an existing LLM gateway or proxy to apply policies centrally?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai





##### Perplexity





##### Chatgpt-search

| Display name | Position |
| --- | --- |
| Lakera | 1 |


- Prompt text: What AI guardrail platforms send alerts into our existing SIEM and security operations workflow?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai





##### Perplexity





##### Chatgpt-search

| Display name | Position |
| --- | --- |
| HiddenLayer | 1 |
| Lakera | 2 |


- Prompt text: What are my options for tools that discover which AI apps, models and agents employees are using across the company, and enforce policies on them?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai





##### Perplexity





##### Chatgpt-search

| Display name | Position |
| --- | --- |
| Noma Security | 5 |


- Prompt text: Which LLM guardrail services add the least latency to each request, so a real-time chat or voice experience isn't slowed?


#### Brand position by platform

Google-ai: Not available
Perplexity: Not available
Chatgpt-search: Not available



#### Platform rows



##### Google-ai





##### Perplexity





##### Chatgpt-search







## Top sources





## Response excerpts

| Prompt text | Platform | Excerpt |
| --- | --- | --- |
| Which AI security products integrate with an existing LLM gateway or proxy to apply policies centrally? | google-ai | Arthur Shield * Integration Approach: Integrates with LLM gateways and orchestration frameworks to monitor and sanitize inputs and outputs dynamically. |
| What are my options for LLM guardrails with a free tier so a startup can test jailbreak and data-leak screening before paying? | chatgpt-search | ...ction, jailbreaks and sensitive-data protection \| \| Pangea AI Guard \| Runtime AI security and input/output screening \| \| Arthur Shield \| LLM monitoring, PII and security \| \| Fiddler \| AI observability and guardrails \| I would ask each vendor for trial c... |



## Competitor excerpts

| Platform | Competitor name | Excerpt |
| --- | --- | --- |
| perplexity | Lakera | Lakera Guard (now Check Point AI Guardrails) is the clearest match in the search results. |
| chatgpt-search | Lakera | ## Shortlist of LLM security tools These are the strongest candidates to evaluate: 1. Check Point AI Guardrails (Lakera) Strong model-agnostic option - Model-independent HTTP API. |
| chatgpt-search | Lasso Security | Sources: Introduction to AI Agent SecurityAPI Overview Documentation 2. Lasso Security Strong framework/gateway independence - Integrates with Kong, Envoy, TrueFoundry, Portkey and LiteLLM. |
| google-ai | HiddenLayer | HiddenLayer (Model Scanning): One of the leading enterprise solutions for ML security. |
| chatgpt-search | HiddenLayer | ## Platforms worth evaluating \| Platform \| Type \| Main security capabilities \| \| --- \| --- \| --- \| \| HiddenLayer Model Scanner \| Commercial \| Malware, backdoors, vulnerabilities, model integrity, and model lineage. |
| chatgpt-search | Lakera | The strongest initial candidates are Check Point Lakera, Netskope AI Guardrails, SentinelOne Prompt Security, and Radware LLM Firewall. |
| perplexity | Guardrails AI | The strongest matches are Guardrails AI and NVIDIA NeMo Guardrails. Both let engineers define custom checks and policies, but “production-ready” needs qualification: the open-source frameworks provide deployable components; production reliability... |
| perplexity | Lakera | \| Option \| Why it’s practical for a small team \| Caveat \| \|---\|---\|---\| \| Lakera Guard \| Self-serve Community access offers up to 10,000 requests/month. |



## Trend

Visibility delta: -1.3333333333333335
Avg position delta: Not available
Citation count delta: -3