Best LLM Gateways for Developers (2026): 9 Compared

The best LLM gateway depends on what you want the gateway to own. RouterPlex, OpenRouter, Requesty, and AgentRouter can bundle access to models behind one account. LiteLLM, Portkey, and Helicone usually sit in front of provider relationships you control. Fireworks AI and Together AI run model inference infrastructure and overlap with gateways without being the same product category.

This comparison separates those responsibility boundaries before comparing feature lists.

LLM gateway comparison #

RouterPlex #

RouterPlex is a hosted gateway for developers who want model access included rather than bringing separate vendor accounts. One prepaid balance covers 37 curated models across 14 providers through OpenAI- and Anthropic-compatible endpoints.

RouterPlex charges supported models at vendor list price and adds no card or crypto top-up fee. Every key can carry a hard lifetime budget, and the prepaid account balance stops at zero.

The limitation is deliberate: the catalog is much smaller than OpenRouter or Requesty. RouterPlex fits mainstream Claude, GPT, Gemini, DeepSeek, Qwen, Kimi, and similar workloads, not every niche community model.

Best for: indie developers and small teams that value billing simplicity and spend containment.

OpenRouter #

OpenRouter is the category leader for broad hosted model access. It offers hundreds of models, multiple providers for many models, routing controls, and an active developer ecosystem.

OpenRouter says it passes through provider token prices, then charges when credits are purchased. Its published card fee was 5.5% with a $0.80 minimum and its crypto fee was 5% when checked July 19, 2026.

Best for: developers who need the broadest catalog or provider-routing depth and accept the funding fee.

Read the OpenRouter alternatives comparison or the detailed OpenRouter pricing and fee math.

Requesty #

Requesty describes itself as an AI gateway and LLM router for more than 600 models. It emphasizes routing, provider access, observability, and enterprise gateway features.

OpenSEO shows Requesty earning search traffic from model directories, cheapest-model rankings, and provider pages. That is useful evidence of its product shape: it competes as both a gateway and a model-discovery layer.

Best for: teams that want a large managed catalog and routing features. Compare billing, supported endpoints, logging, and data terms for the exact models you use.

AgentRouter #

AgentRouter is a hosted unified API aimed heavily at coding-tool users. Its public messaging emphasizes free quota, Claude Code compatibility, and access to multiple model families.

The tradeoff is confidence. Its public search footprint is small, and promotional affiliate content makes strong free-credit claims without the depth of pricing, privacy, support, or sustainability evidence available from larger services. Treat free quota as a test budget, not a production guarantee.

Best for: non-sensitive experiments where the current free offer is worth testing. Avoid making it a single point of failure until service terms, data handling, and support meet your requirements.

Fireworks AI #

Fireworks AI is primarily an inference platform for generative and open-weight models. It offers serverless inference, deployments, fine-tuning, and model-serving infrastructure.

That is not the same purchase as a neutral wallet spanning every proprietary model vendor. Fireworks competes when you want fast inference for models it hosts, especially open models, and are willing to choose the serving platform as well as the model.

OpenSEO shows Fireworks ranking strongly for open source LLMs, inference providers, and model-specific queries. That matches its infrastructure position.

Best for: production open-model inference, deployment control, and performance work.

Together AI #

Together AI is an AI cloud for model inference, dedicated endpoints, and training. Like Fireworks, it runs model infrastructure rather than acting only as a billing and routing layer over unrelated vendors.

Together earns organic visibility through model pages for DeepSeek, Kimi, Sora, and other hosted models. Choose it when the desired model and deployment mode are available directly on Together.

Best for: teams building on open or hosted models that want inference infrastructure and optional dedicated capacity.

LiteLLM #

LiteLLM is an open-source SDK and proxy that normalizes many model-provider APIs. In a self-hosted setup, you keep the provider accounts, credentials, infrastructure, database, upgrades, and incident response.

LiteLLM removes protocol fragmentation but not vendor-account fragmentation. That is a good trade when your team already has contracts and needs control over the proxy boundary.

Best for: platform teams with provider relationships and engineers available to own the gateway. Read the LiteLLM alternatives and self-hosting guide.

Portkey #

Portkey combines an AI gateway with routing, reliability, access controls, observability, and governance features.

Portkey is relevant when the gateway is an organization control plane rather than merely a cheaper way to buy tokens. Evaluate it on policy, auditability, data controls, and how it connects to existing provider accounts.

Best for: teams standardizing model access across several applications or business units.

Helicone #

Helicone leads with LLM observability and adds gateway capabilities such as caching, routing, and request controls.

Choose Helicone when the primary pain is understanding production model behavior: cost, latency, errors, prompts, traces, and cache performance. Decide separately whether model access should come through direct provider accounts or another aggregator.

Best for: AI applications that already call models and need better telemetry.

Which LLM gateway should you choose? #

Use the responsibility boundary first:

Then test the final two with the same requests. Verify streaming, tool calls, structured output, context limits, error behavior, data retention, and final billed cost.

Cost questions most comparisons miss #

Ask each provider:

1. Is there a markup on model tokens?
2. Is there a fee when purchasing credits?
3. Does BYOK usage have a platform fee?
4. Is observability priced separately?
5. Can balances become negative?
6. Can each key enforce a hard server-side budget?
7. Do credits expire or become non-refundable?
8. What happens when billing state is unavailable?

The cheapest-looking model rate can still produce a more expensive account if funding fees, minimums, or operational work are excluded.

If your shortlist starts with one hosted balance and hard spend limits, run a $5 RouterPlex test. Use a dedicated key, replay a representative workload, and compare the exact billed amount before moving traffic.