Google Agent Development Kit (ADK) vs Perplexity Comet

A side-by-side look at pricing, capabilities, pros, cons, and our editorial scores.

	Google Agent Development Kit (ADK) Agents	Perplexity Comet Agents
Tagline	Google's open-source framework for building, evaluating, and deploying production AI agents	An agentic AI browser from Perplexity that reads, reasons over, and acts on the pages you're viewing.
Category	Agents	Agents
Pricing	Free· Framework itself is free and open-source (Apache 2.0). Costs come from the underlying model provider (e.g. Gemini API / Vertex AI usage) and any hosting infrastructure (Cloud Run, GKE, Agent Engine).	Freemium· Basic: $10 · Pro: $25 · Enterprise: Contact sales
Model	Gemini (default) plus Claude, GPT-4/5, Llama, and other providers via LiteLLM	Routes to Perplexity Sonar plus frontier models (OpenAI GPT, Anthropic Claude, Google Gemini) depending on task and subscription tier
Editorial score	—	—
Use cases	Multi-agent research assistantCustomer support triage agentRAG chatbot backed by Vertex AI SearchCode review and refactoring agentBigQuery natural-language analytics agentDocument processing pipelineVoice/streaming conversational agentInternal tool-use agent orchestrating APIsEvaluation and regression testing of LLM workflowsEnterprise workflow automation on Agent Engine	Multi-tab research synthesis with citationsAgentic email triage and drafting in GmailAutomated form filling and account signupsCross-site product comparison tablesMeeting scheduling from inbox contextLong-document and PDF summarisationStructured data extraction from web tablesGuided shopping and price comparisonNewsletter and subscription cleanupIn-context follow-up questions about the current page
Pros	Genuinely open-source (Apache 2.0) with active Google engineering behind it, not a hosted-only product Multi-language: first-class Python, Java, and Go SDKs — rare among agent frameworks that are usually Python-only Built-in dev UI (`adk web`) with trace inspection, event stream, and session replay speeds up debugging enormously Model-agnostic via LiteLLM — Gemini is default but Claude, GPT, and local models plug in cleanly Rich multi-agent primitives out of the box: SequentialAgent, ParallelAgent, LoopAgent, and hierarchical sub-agents Tight Google Cloud integration for deployment (Cloud Run, GKE, Agent Engine) plus native BigQuery/Vertex Search tools Evaluation harness with trajectory-level scoring is included, not a separate paid add-on First-class MCP (Model Context Protocol) client and server support	Agent can actually act on live sites — send email, book, buy, fill forms — not just answer questions about them. Assistant has direct access to the current page and other open tabs, so answers stay grounded in what you're looking at. Chromium-based, so existing extensions, logins, bookmarks and Chrome workflows transfer without friction. Free tier is generous since October 2025; you don't need a Pro sub to try the core agentic browsing experience. Answers are cited back to source URLs, inheriting Perplexity's citation-first UX. Cross-platform: macOS, Windows, Android and iOS all supported.
Cons	Documentation and examples lean heavily on Gemini + Google Cloud; non-Google paths work but feel like second-class citizens API surface is still evolving — breaking changes between minor versions have been common through 2025-2026 Multi-agent orchestration primitives are powerful but the graph/callback model has a real learning curve compared to a plain prompt loop Agent Engine deployment is convenient but locks you into GCP billing and quotas TypeScript/Kotlin support lags the Python SDK in features and community examples	Security researchers have demonstrated prompt-injection style attacks ('CometJacking') that can exfiltrate data from connected accounts — a real risk when granting the agent Gmail or calendar access. Agent runs on complex sites (checkout flows, dashboards) are still brittle and often need supervision or correction. Best models and longest agent sessions are gated behind Pro ($20/mo) or Max — the free tier throttles the most useful capabilities. Installing a whole new browser is a bigger commitment than a Chrome extension for users who just want an AI sidebar. No public API for the Comet agent itself; automation has to happen inside the browser UI, not via a callable endpoint. Privacy footprint is significant — the assistant sees page contents, tabs and, if authorised, mailbox and calendar data.
Website	google.github.io	comet.perplexity.ai

Pick Google Agent Development Kit (ADK) if

✅ Genuinely open-source (Apache 2.0) with active Google engineering behind it, not a hosted-only product
✅ Multi-language: first-class Python, Java, and Go SDKs — rare among agent frameworks that are usually Python-only
✅ Built-in dev UI (`adk web`) with trace inspection, event stream, and session replay speeds up debugging enormously
✅ Model-agnostic via LiteLLM — Gemini is default but Claude, GPT, and local models plug in cleanly

Pick Perplexity Comet if

✅ Agent can actually act on live sites — send email, book, buy, fill forms — not just answer questions about them.
✅ Assistant has direct access to the current page and other open tabs, so answers stay grounded in what you're looking at.
✅ Chromium-based, so existing extensions, logins, bookmarks and Chrome workflows transfer without friction.
✅ Free tier is generous since October 2025; you don't need a Pro sub to try the core agentic browsing experience.

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