Best Prompt Injection Detection Tools in 2026

The prompt injection detection landscape has grown significantly over the past year. If you are building an LLM-powered application, you have several options for protecting it. Here is a breakdown of the leading tools in 2026.

1. Bordair

Type: Managed API

Modalities: Text, image, document, audio

Latency: Under 50ms

Pricing: Free tier (1,000 scans/month), paid plans from affordable tiers

Bordair uses a three-stage detection pipeline combining pattern matching, a fast-accept gate, and a fine-tuned DeBERTa v3 classifier. It is the only tool on this list with native multimodal support across all four input types. Output scanning with custom regex rules is available on paid plans.

Best for: Teams that need multimodal detection with minimal integration effort.

2. Lakera Guard

Type: Managed API

Modalities: Primarily text

Latency: Varies

Pricing: Enterprise-focused

Lakera Guard is one of the more established products, backed by significant funding. It focuses on text-based prompt injection and jailbreak detection. Enterprise pricing and sales-driven onboarding.

Best for: Enterprise teams with existing Lakera contracts.

3. Meta PromptGuard

Type: Open-source model

Modalities: Text only

Latency: Depends on your infrastructure

Pricing: Free (MIT licence)

A fine-tuned mDeBERTa model from Meta. Good baseline performance but requires self-hosting, and you are responsible for infrastructure, scaling, and updates. Text-only.

Best for: Teams with ML engineering resources who want full model control.

4. Rebuff

Type: Open-source framework

Modalities: Text only

Latency: 1-3 seconds (LLM-in-the-loop)

Pricing: Free (open source)

Multi-layered approach using heuristics, LLM classification, vector similarity, and canary tokens. The LLM dependency adds latency and cost, and creates a recursive attack surface.

Best for: Research and experimentation with detection approaches.

5. Vigil

Type: Open-source scanner

Modalities: Text only

Latency: 100-500ms (self-hosted)

Pricing: Free (open source)

Self-hosted Python service with YARA-like rules, vector similarity, and transformer classification. Customisable but requires infrastructure management.

Best for: Teams who want deep control over detection rules.

Summary

Tool	Multimodal	Managed	Latency	Output Scanning
Bordair	Yes (4 modalities)	Yes	<50ms	Yes
Lakera Guard	Limited	Yes	Varies	Limited
PromptGuard	No	No	Varies	No
Rebuff	No	No	1-3s	No
Vigil	No	No	100-500ms	No

If multimodal detection, low latency, and ease of integration are priorities, give Bordair a try.