FastRouter.ai (site) is a unified AI gateway that routes requests across 200+ LLMs through one OpenAI-compatible API, optimizing for cost, latency, quality, and reliability. It has a free Starter plan, then paid tiers starting at $199/month (Pro), $799/month (Business), and custom Enterprise pricing, with no markup on model costs. If that entry price is more than you need, here are five cheaper LLM routing tools, ordered from least to most expensive.
Comparison table
| Product | Free tier | Starts at | Best for |
|---|---|---|---|
| zinroute | Yes | $0/mo | Teams wanting savings-based pricing with no upfront cost |
| Multiroute AI | Yes | $0.0005/mo | Pay-per-request routing with your own API keys |
| CustomRouter | Yes | $7.99/mo | Developers who want a low-cost plan or self-hosting |
| Smart Router — AI API Gateway | No | $18.97/mo | Buyers who want a one-time purchase with source code |
| LLMLite | Yes | $29/mo | Teams with predictable, higher-volume token usage |
zinroute
zinroute (site) cuts LLM costs through smart routing and optimization. Its current free early access tier covers up to $5,000/month in OpenAI spend at no cost. After early access, pricing becomes performance-based: 10% of verified savings generated, with no fee if no savings are achieved. This suits teams that want to try routing without committing to a subscription. The limitation is that pricing details beyond early access are tied to savings calculations rather than a fixed rate, so costs are less predictable than a flat monthly plan.
Multiroute AI - smart LLM router
Multiroute AI (site) offers one API for every LLM, tuned per task, with a BYOK (bring your own key) model. The free tier includes a $5 sign-up credit with no credit card required. Paid usage is $0.0005 per routed platform request, or $5.00 per 10,000 requests. This fits developers who want granular, usage-based billing rather than a flat subscription. Because it's BYOK, you still pay your model providers directly for the underlying API calls — Multiroute's fee covers routing only, not model costs.
CustomRouter
CustomRouter (site) is LLM routing built around flexibility, including a self-hosting option under the open-source AGPL-3.0 license. The free tier allows 500 requests/day; the Developer paid tier is $7.99/month (or $60/year), with a custom-priced Enterprise tier above that. It suits developers who want either a cheap hosted plan or full control via self-hosting. One limitation: the free tier's 500 requests/day cap may be tight for apps with steady daily traffic.
Smart Router — AI API Gateway
Smart Router (site) is an AI API gateway aimed at cutting API costs by 50-80% automatically. It's sold as a one-time purchase of SGD 25.59 (about USD 18.97), which includes the full Python source code, a dashboard UI, and documentation. This suits developers who prefer owning the code outright over a recurring subscription. The notable limitation is there's no free tier, and because it's a one-time code purchase rather than a hosted service, you're responsible for running and maintaining it yourself.
LLMLite
LLMLite (site) gives you one API endpoint to route prompts, aiming to cut costs and downtime. The free tier includes 100K tokens/month; paid plans start at $29/month for Pro (10M tokens/month), $99/month for Max (100M tokens/month), with custom Enterprise pricing above that. It suits teams with higher, more predictable token volumes who want clear monthly caps. The limitation is that it's the most expensive option here, so it only makes sense once your usage outgrows the cheaper per-request or lower-tier plans.
How to choose
If you have light or unpredictable usage, start with zinroute's free tier or Multiroute AI's pay-per-request model since neither locks you into a monthly fee. If you want a cheap fixed subscription or the option to self-host, CustomRouter is the lowest committed price. For teams with steady, higher-volume token needs, LLMLite's tiered plans give clearer cost ceilings, while Smart Router suits anyone who'd rather buy source code outright than pay monthly.
FAQ
Is FastRouter.ai's free tier comparable to these alternatives' free tiers? The brief states FastRouter has a free Starter plan forever with core gateway features, but doesn't list specific usage limits to compare directly.
Which alternative is cheapest overall? zinroute's free early access tier ($0/mo, up to $5,000/month OpenAI spend) and Multiroute AI's $0.0005-per-request pricing are the two lowest-cost entry points listed.
Do any of these alternatives require using your own API keys? Multiroute AI is explicitly BYOK; the brief doesn't state this requirement for the other alternatives.