The Best LLM Gateways in 2026, by Workload
No single best LLM gateway exists; workloads pick winners. OpenRouter for multi-model apps, LiteLLM for platform teams, Portkey for observability, ProxyLLM for flat OpenAI volume.
There is no best LLM gateway, only a best gateway for a workload, and any ranked top ten hides the axis that decides the purchase. Four workloads cover most buyers in 2026: multi-model apps belong on OpenRouter, platform teams that self-host belong on LiteLLM, observability-first organizations belong on Portkey, and OpenAI-heavy volume that should cost the same every month belongs on a subscription-backed lane, which is the one we sell. ProxyLLM is our product; everything below says plainly where it loses.
Why “best” is a workload question
A gateway is the layer every LLM call passes through, so the right one is decided by what your calls need: breadth, control, visibility, or a different cost model. Those pull in different directions. The marketplace with 400 models cannot also be the self-hosted router on your own metal, and neither changes what a token costs. Lists that rank gateways one through ten are really ranking how closely each tool matches the list author’s workload.
So this roundup is organized the only honest way: by the job.
Multi-model apps: OpenRouter
If your product switches between OpenAI, Anthropic, Google, and open-weight models, or your team experiments faster than procurement can issue keys, OpenRouter is the default for a reason. One key reaches 400+ models, failover routes around dead hosts, responses stream, and the price is provider passthrough plus a fee of roughly 5.5% on credits as of June 2026.
Where it loses: the fee compounds at volume, and an OpenAI-only app is paying for breadth it never touches. The field of contenders around it, Requesty and direct keys included, is sorted in OpenRouter alternatives.
Platform teams that self-host: LiteLLM
LiteLLM is the gateway you operate: an open-source proxy speaking the OpenAI format across 100+ providers, with virtual keys, per-key budgets, rate limits, fallback chains, and logging callbacks. No gateway fee exists because no gateway company sits in the path; you pay providers at list price and carry the ops.
Where it loses: the cost is denominated in engineer hours, and honest accounting puts self-hosting at a few hundred dollars a month of attention regardless of traffic. Teams without platform capacity should buy hosted and move on.
Agencies and client work: scoped keys over a predictable cost
Agencies have a sharper requirement than most lists notice: every client needs its own key, budget, and usage log, and the agency needs margins that survive a client’s traffic spike. Two setups deliver it. LiteLLM’s virtual keys with per-key budgets work well if you self-host. Our version: ProxyLLM issues scoped sub-keys with per-key caps and per-key request logs, sitting on top of a flat-cost OpenAI lane, so client work draws from capacity with a known monthly price instead of an open meter. Disclosure stands: this is our product, and for agencies running mostly non-OpenAI models, LiteLLM is the better answer.
Observability-first: Portkey, with Langfuse alongside
When the requirement is knowing what every request did, what it cost, and whether it obeyed policy, Portkey bundles logs, traces, guardrails, and caching into one hosted control plane over your own keys. Langfuse covers the deeper engineering loop, traces and evals, as open source. The whole observability landscape, including what changed at Helicone in 2026, is mapped in Helicone alternatives.
Where the category loses: visibility organizes a metered bill without shrinking it. Perfect dashboards over a growing meter are still a growing meter.
Flat-rate OpenAI volume: ProxyLLM
Our lane, with the disclosure repeated. Codex Hosted runs OpenAI’s official, unmodified Codex CLI on managed servers, signed in with your own ChatGPT account through OpenAI’s device-code flow, and serves it as an OpenAI-compatible endpoint. OpenAI-bound volume bills to the flat subscription instead of the per-token meter: $129 a month, no inference markup, with fallback to a second account and then your own API key when a plan window fills.
Predictability is the product; the savings follow from it. By our planning estimates, a Plus plan absorbs roughly $700 of API-equivalent work a month, Pro 5x roughly $3,500, Pro 20x roughly $14,000, always estimates, never guarantees. A $3,500 metered month mapping to about $229 flat is the arithmetic that ends most gateway debates, when the traffic is OpenAI-shaped.
Where it loses, plainly: the flat lane is OpenAI-only, the Codex lane returns complete responses rather than streams, and below roughly $150 a month of OpenAI spend the fee outweighs the meter. The direct comparison with the marketplace model is in ProxyLLM vs OpenRouter.
The comparison table
| Gateway | Cost model | Wins for | Loses when |
|---|---|---|---|
| OpenRouter | Per token + ~5.5% credit fee | Multi-model apps, experimentation | Single-provider traffic at volume |
| LiteLLM | Free OSS + your infra and hours | Self-hosting platform teams | No ops capacity to spend |
| Portkey | SaaS plans, keys bill at cost | Observability and governance | You only needed a request log |
| ProxyLLM | $129/mo flat + your ChatGPT plan | OpenAI-heavy volume, agencies | Non-OpenAI models, streaming UIs, low spend |
| No gateway | Provider list price | One provider, simple traffic | You need budgets, logs, or breadth |
How to choose in five minutes
Count your providers, then look at your OpenAI line item. Multiple providers and real breadth needs: OpenRouter hosted, LiteLLM self-hosted. Governance requirements: Portkey. One provider and a bill under $150: skip the gateway entirely. And if the OpenAI line is most of your spend and growing, the cost model matters more than the routing; the full decision framework is in per-token vs flat-rate pricing.
If that last profile is yours, the calculator maps your current monthly spend to the flat-lane math in about thirty seconds.
Frequently asked questions
What is the best LLM gateway in 2026?
There is no single best, because gateways optimize for different workloads. OpenRouter is the strongest pick for multi-model apps, LiteLLM for platform teams that self-host, Portkey for observability and governance, and ProxyLLM, which is our product, for flat-cost OpenAI volume on your own ChatGPT subscription.
Do LLM gateways charge fees?
Three fee shapes exist. Open-source routers like LiteLLM are free software plus your infrastructure and maintenance. Marketplaces like OpenRouter charge roughly 5.5% on credit purchases as of June 2026. SaaS gateways like Portkey charge platform plans while your provider keys bill at cost. ProxyLLM charges $129 a month flat with no inference markup.
Which LLM gateway is best for agencies?
Agencies need per-client keys, budgets, and predictable margins. LiteLLM delivers virtual keys and budgets if you can self-host. ProxyLLM, our product, issues scoped sub-keys with per-key caps and logs on top of a flat-cost OpenAI lane, which turns client inference from a variable cost into a fixed one.
Is there a flat-rate LLM gateway?
For OpenAI workloads, yes. ProxyLLM's Codex Hosted runs OpenAI's official Codex CLI signed in with your own ChatGPT account and serves it as an OpenAI-compatible endpoint, so usage bills to the flat subscription. Capacity follows your plan's usage windows: we estimate a Plus plan absorbs roughly $700 of API-equivalent work monthly and Pro tiers roughly $3,500 to $14,000, as estimates rather than guarantees.
Do I need an LLM gateway at all?
Not always. A single-provider app spending under about $150 a month is usually better served by a direct API key and a retry wrapper. Gateways earn their place when you juggle multiple providers, need per-team budgets and logs, or want to change what the traffic costs.