Caido

Overview

Caido is a web security auditing toolkit for people who need to inspect and work through web traffic during security assessments. It is best suited to pentesters, security engineers, and bug bounty hunters who want manual testing supported by automation and optional AI connections. Its free plan offers a concrete way to start, but its caps are tight and paid plans beyond the entry price need careful cost comparison.

Founded in 2021, Caido describes itself as bootstrapped and independent. It supports web, API, and mobile testing, along with finding management. Readers comparing the category can browse Penetration Testing Software.

Key features

Traffic inspection and filtering

Caido’s proxy intercepts and monitors HTTP and WebSocket traffic, and retains history for intercepted traffic and WebSocket messages. That combination gives testers material to revisit during an assessment rather than relying only on what is visible in the moment. HTTPQL filtering searches requests and responses, which is useful when a growing traffic history makes manual review unwieldy.

Automation, extensions, and AI

Node-based workflows support ad-hoc automation, while automated attacks can use custom payloads and placeholders. These capabilities suit testers who want to repeat or adapt tasks without making every step manual. Community plugins and custom extensions broaden the toolkit, though Basic’s three-plugin ceiling may constrain users who depend on several extensions.

Users can connect an existing LLM provider, including Anthropic, Google, OpenAI, and providers available through OpenRouter. AI agents can also access Caido programmatically through its Client SDK. That flexibility is useful for teams already working with these providers; it does not remove the need to supply an existing provider connection.

Pricing

Caido is freemium, with Basic at free, billed Free forever. It allows two projects, seven workflows, three plugins, five filter presets, and one pipeline session at a time. That is a reasonable starting point for an individual learning the toolkit or handling limited work, but the project and session caps make it a poor fit for broader concurrent use.

The Education Plan is free for a one-year license for students and teachers at accredited institutions. Its defined eligibility and term make it a useful route for an eligible classroom or student, but not a permanent free tier.

Individual offers unlimited projects and workflows, AI Assistant, nightly builds, and one user, with monthly or yearly billing. Team is priced per seat on a monthly or yearly basis and adds shared instances, reassignable licenses, and a dedicated support channel. Enterprise uses custom pricing per seat and adds unlimited users, purchase orders, and custom integrations built on request. The opened pricing page did not show prices for these named plans; the stated paid starting point is $20/user/mo, so buyers should confirm the applicable plan cost before scaling beyond Basic.

Basic and Individual include public Discord support; Team has a dedicated support channel. Caido offers no free trial, so the free plans are the available no-cost way to evaluate the product. Basic’s project, workflow, plugin, filter-preset, and session limits are the principal trade-off for avoiding a paid plan.

Platforms

Caido supports API, Linux, macOS, self-hosted, web, and Windows. The platform range serves teams spanning desktop and web environments, while self-hosting may suit organizations that want to run their own instance. Caido says it collects account name, email, and user-agent at registration, and instance IP addresses plus API-call actions and timestamps when connecting to cloud services; it says it does not collect instance data or in-app activity. Its Trust Portal lets visitors request access to trust documents.

Who it's for

Caido is a strong fit for pentesters, security engineers, and bug bounty hunters who need traffic inspection, request search, and configurable workflow automation in a toolkit that can connect to existing LLM providers. The free tier is most suitable for modest individual use, while shared instances and reassigned licenses make Team more relevant to collaborative work. Readers who need room for more than one pipeline session at once or extensive plugin use should look beyond Basic.

Pros and cons

Pros: HTTP and WebSocket interception with traffic and message history gives testers a reviewable record.

Pros: HTTPQL search, node-based workflows, and payload-based automated attacks cover both analysis and repeatable work.

Pros: Existing LLM provider connections and Client SDK access let users incorporate AI without being limited to a single named provider.

Cons: Basic permits only one pipeline session at a time, alongside caps of two projects, seven workflows, three plugins, and five filter presets.

Cons: Prices for Individual and Team are not shown on the opened pricing page, complicating cost comparisons for users who outgrow Basic.

Cons: The Education Plan lasts one year, so it is not a permanent free option for eligible educators or students.

Alternatives

Choose Dradis if an open-source, free-forever Community Edition with one project at a time and community forum support better fits the assessment workflow; it also offers a free trial. Pentesterra is worth comparing for its free DevGuard tier, which provides one project, three scans per month, and CLI, IDE plugin, and web console access with community support. Pick RedAmon when a free MIT-licensed, self-hosted Docker stack for commercial or personal use is the better fit.

Kali Linux is a free, open-source distribution. PenPeeper is free for personal or professional work, but cannot be sold or hosted as a paid SaaS without permission. Aircrack-ng provides a full software suite with no license fee. Burp Suite DAST offers a tailored solution with a free trial and pricing dependent on portfolio. OWASP Amass is a free, open-source framework under the Apache License 2.0.

Verdict

Caido is a sound choice for individual security testers and small teams who want HTTP and WebSocket inspection, searchable traffic, workflow automation, and the option to connect their existing AI provider. Its free Basic plan makes initial use accessible, but the session and project caps are restrictive for heavier work, and buyers should establish paid-plan pricing before committing to growth. Look elsewhere if your choice depends on known upgrade costs or a less constrained free workflow.