Which AI APIs Have a Free Tier? An Honest Breakdown

By the Zylo team · Updated June 8, 2026 · 4 min read

The phrase free tier gets used loosely across the AI industry, and the confusion costs developers real money. Some providers offer a permanent free tier with a recurring allowance, others hand out one-time trial credits that expire, and still others simply give you a free key whose every call is billed. These are three different things, and mixing them up leads to surprise invoices or abandoned projects. This guide separates the concepts, surveys what is genuinely available, and explains the Zylo free tier honestly — what it includes, where its limits sit, and which models it does not cover — so you can plan around what is real rather than what a headline implies.

Free tier, trial credits, and free keys are not the same

A genuine free tier is a recurring allowance: a quota that refreshes, usually daily or monthly, that you can rely on indefinitely as long as you stay within its limits. Trial credits are different — a fixed pool of value, often granted at signup, that drains as you use it and is gone once spent or expired, after which you pay full price. A free key is different again: it costs nothing to obtain and may unlock paid models, but every token still bills against credits, so the key being free does not make the usage free. Many providers advertise one of these and let buyers assume another. The honest framing is that a free key plus trial credits is not the same as a standing free tier, and only a recurring allowance lets you run real, ongoing traffic without a card. Our guide to a free AI API key covers the key side of this in detail.

What Zylo includes in its free tier

Zylo offers a genuine free tier through the Basic plan, and it requires no card. The recurring daily allowance is real: roughly 200,000 tokens and 7,200 requests per day, capped at 10 requests per minute, with input up to 200,000 characters per request, for text. That is enough to power a prototype, a personal project, or a low-volume internal tool indefinitely without spending anything. You obtain a key, point your OpenAI SDK at https://api.zyloai.net/v1, and start calling immediately. Because the allowance refreshes each day rather than draining like trial credits, it behaves the way a free tier should — predictable and ongoing — rather than expiring after a burst of testing. The trade-off, covered next, is which models that allowance reaches.

The honest limits and which models are covered

The Basic free tier serves Basic-tier models only: lightweight options such as a Google Flash-Lite class model and a gpt-5-nano-class model. These are capable for chat, classification, summaries, and high-volume simple work, but they are not the frontier models. Premium models — Claude Opus 4.8, GPT-5.5, Gemini 3.1 Pro, DeepSeek V4 — are not part of the free tier. They are billed per token from credits and require a paid plan from Go upward, and genuinely free unlimited access to frontier models does not exist anywhere, because inference costs real compute. The free tier is also text only and carries the rate limits noted above, so it is not a substitute for paid capacity at scale. Within those honest boundaries it is a real, useful, recurring free allowance — not a trial that vanishes. You can see exactly which models sit in each tier on the models page.

Choosing between free and paid

The right plan depends on what you are building. If your workload is high-volume but simple — chatbots, tagging, short summaries — the free Basic tier and its lightweight models may carry you a long way at zero cost. If you need frontier reasoning, coding strength, or long-context analysis, you will need a paid plan and credits, but even then Zylo bills usage at base per-token rates with no markup; the only added fee is a flat 25 percent charge when you add credits, applied once rather than on every call. That structure means upgrading does not penalize you per token as you scale. A sensible path is to start free, validate your idea on Basic-tier models, and move premium-dependent paths onto credits only when the quality genuinely requires it. Review the tiers and current rates on the pricing page, and if you specifically want a large no-cost allowance, see our note on a free unlimited AI API for an honest look at what unlimited really means.