Once an API leaves a side project and reaches real users, someone has to answer three questions: who's allowed to call it, how many times a minute, and what happens when traffic spikes or a key leaks. Unkey and Kong both answer those questions, but they come from opposite ends of the market — and Unkey directly names Kong as the alternative you'd otherwise reach for.
Unkey
Unkey is a single place to deploy an API, issue and revoke its API keys, rate-limit it, and watch its logs — instead of wiring together four separate services to do each job. It's open source under the AGPL license, so the whole thing is auditable rather than a black box, and its billing model charges only for what actually runs: no cost during idle periods. A self-service developer portal lets your own users manage their API keys without filing a support ticket.
Price: free up to 150K requests/month for API key management. Pro tier from $25 to $1,000/month depending on volume (250K to 100M requests/month). Deploy pricing starts at $5–$50/month base plus compute usage (about $0.000006944/vCPU-second) plus network egress.
Strengths: genuinely open source and auditable, one platform instead of four glued-together services, and a pay-for-what-runs billing model that doesn't charge you for downtime.
Watch out for: it's a generalist tool — less fine-grained control than a purpose-built gateway like Kong if you need deep plugin-level customization. The compute billing model is worth watching closely for spiky, irregular workloads, and the Pro tier can reach $1,000/month at high volume. Its founding date isn't publicly disclosed, so track record is harder to verify than an established player.
Kong
Kong is one of the most widely used API gateways on the market — the layer that sits in front of a company's APIs to route, secure, rate-limit and monitor traffic — with years of production use behind it. It's now expanding into managing AI model traffic the same way it manages regular API traffic: token cost optimization and semantic caching for LLM calls. The ecosystem goes beyond the gateway itself, including a service mesh and the well-known Insomnia API client.
Price: Kong Gateway (open source) is free. Kong Konnect, the managed cloud version, has pricing that isn't publicly listed. Kong for Startups offers up to $100K in credits plus 50% off the AI Gateway.
Strengths: a free, open-source tier with years of proven production use, genuine coverage of AI/LLM traffic (not just an add-on), and a generous startup credits program.
Watch out for: Konnect's cloud pricing isn't public, so budgeting requires a sales conversation. It's meaningfully more complex to operate than a simple API documentation or key-management tool, and it's competing directly against AWS API Gateway, Google's Apigee and Salesforce's MuleSoft — all enterprise giants with deep pockets.
Unkey vs Kong at a glance
| Unkey | Kong | |
|---|---|---|
| License | Open source (AGPL) | Open source (Kong Gateway) |
| Scope | API keys, rate limiting, deployment, logs — one bundle | Full API gateway: routing, security, mesh, AI traffic |
| Starting price | Free up to 150K req/mo → $25–$1,000/mo | Free (self-hosted Gateway) → Konnect pricing on request |
| Operational complexity | Lower — single platform, quick to adopt | Higher — full gateway to configure and run |
| Track record | Newer, founding date undisclosed | Years in production at enterprise scale |
| Best fit | Small teams wanting keys + rate limiting without a big lift | Platform teams and enterprises needing a full gateway |
Verdict
Pick Unkey if you're a small-to-mid engineering team that just needs API keys, rate limiting and deployment handled well without standing up a full gateway — the free tier covers real usage (150K requests/month) and the AGPL license means you can audit exactly what's running. Pick Kong if you're a platform team at a larger company that needs a proven, full-featured gateway — routing, security policies, a service mesh, and now AI traffic management — and you have the operational capacity to run it properly. The honest dividing line is scope: Unkey solves the API-keys-and-rate-limiting problem well and stops there; Kong solves that problem as one piece of a much bigger, more complex platform.