How Do You Get an API Key for OpenAI, Anthropic, Gemini, Mistral, Groq and Perplexity? A Beginner's Guide for 2026

‌

When you use a tool or application that says it is "powered by GPT" or "powered by Claude," you are using OpenAI's or Anthropic's technology but not the chat products themselves. Those tools have an API key behind them. That is exactly what this guide helps you get.

‌

What Are the Benefits of Using an AI API Instead of a Chat Product?

Using the API rather than a chat interface gives you three things a chat subscription does not.

• Your prompts become reusable and consistent. In a chat product, every conversation starts fresh. Via the API, you can save, version, and reuse prompts — building a library of tested instructions that produce consistent outputs every time, for every person on your team.
• Your outputs can use your own data. The API lets you inject your organisation's specific context — brand guidelines, product terminology, customer data — into every request programmatically. That makes it easier to standardize outputs across tools and workflows. Chat products are general-purpose; the API is buildable.
• You pay only for what you use. Instead of paying a flat fee like a chat subscription, you pay for input and output tokens as you use them. For structured, repeatable prompts — as opposed to open-ended conversations — API costs per task are typically far lower than a monthly seat.

How Do You Get an OpenAI API Key?

Go to platform.openai.com and sign up or log in. OpenAI requires you to verify your email address and may request a phone number during registration. Once logged in:

1. Open the Billing page — click Billing in the left sidebar and add a payment method. OpenAI billing requirements can change. In many cases, you need to add a payment method or purchase credits before API calls will work. Free trial credits, when available, are limited-time and not guaranteed for all new accounts.
2. Go to API Keys — in the left sidebar, click API Keys.
3. Click Create new secret key — give it a descriptive name so you can identify it later.
4. Copy the key immediately — OpenAI shows your key only once. Store it securely; never commit it to a public repository.

How Do You Get an Anthropic API Key?

Go to console.anthropic.com and click Build with Claude or Sign Up. Anthropic does not use passwords — it sends a one-time magic link to your email address. Click the link to verify and log in.

1. Add a payment method — click Settings → Billing and add a credit card. Anthropic’s API is usage-based and in most cases you need to enable billing or prepaid credits before you can use the key, though promotional or trial credits may occasionally be available.
2. Go to API Keys — in the left sidebar, click API Keys.
3. Click Create Key — give your key a descriptive name.
4. Copy the key immediately — Anthropic shows it only once.

How Do You Get a Google Gemini API Key?

Google AI Studio offers a generous free tier that lets you call Gemini models without adding a credit card, but quotas and model access may change over time. As of 2026, free usage is limited and primarily focused on Flash/Flash-Lite models, with higher tiers and Pro models requiring billing.

1. Go to aistudio.google.com — sign in with your Google account.
2. Click Get API Key — in the left sidebar or top navigation.
3. Create API key in new project — Google creates a project automatically.
4. Copy the key — it remains visible in Google AI Studio, so you can return to it if needed.

Note: To continue using the API without interruption, restrict your key — Google is phasing out unrestricted traffic keys. In AI Studio, click the ‘Restrict to Gemini API’ button (or the current restriction option) to limit where your key can be used and keep it secure.

How Do You Get a Perplexity API Key?

Visit perplexity.ai and sign up using Google, Apple, SSO, or email. Free accounts can generate API keys, but they usually do not include recurring monthly credits. Perplexity Pro subscribers often receive a monthly API credit allowance (for example, around $5), though the exact amount and terms can change, so always confirm in your account billing settings.

1. Go to your Perplexity account settings — click your profile icon in the top right.
2. Open the API section — navigate to Settings → API.
3. Click Generate API key — name your key and confirm.
4. Copy the key immediately — store it securely.

How Do You Get a Mistral API Key?

1. Go to console.mistral.ai — create an account or log in.
2. Add a payment method — Mistral uses usage-based pricing; you need billing set up before your key is active. If Mistral offers any trial credits or promos, they’ll appear in your console; do not assume a permanent free tier.
3. Go to API Keys — the Mistral API key URL is console.mistral.ai/api-keys.
4. Click Create new key — give it a name and set an optional expiry date.
5. Copy the key immediately — Mistral shows your key only once.

How Do You Get a Groq API Key?

Groq offers a free tier account: you can sign up at console.groq.com, create an API key with no credit card, and use their hosted models within rate limits. The free tier is capped by per-minute or per-day limits, so it’s best for experimentation rather than heavy production use.

1. Go to console.groq.com — sign up or log in.
2. Go to API Keys — click the API Keys section in the console.
3. Click Create API Key — give it a descriptive name.
4. Copy the key immediately — Groq will not show the key again once you leave the page.

How Do You Use Your API Keys in Promptitude?

If you use Promptitude, you can store each provider key and reuse it across prompts. Go to Settings → API Keys, select the provider, paste your key, and save.  That lets your team reuse the same provider setup across prompts without re-entering credentials for each workflow. From that point, every prompt in your shared library can use that provider's models — switchable from a dropdown, testable side by side, and deployable via REST API without any code changes.

Your organisation's content storage connects directly to those prompts, so outputs are shaped by your own knowledge base rather than starting from scratch each time.

Ready to connect your API keys? Add your first key to Promptitude →

Quick Reference: Where to Find Each API Key