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How to Get OpenAI API Key in September 2025: Complete Guide

Quick Setup: Create your ChatGPT API key in 5 minutes • Setup billing • Configure limits • Start using GPT-4o and GPT-4o-mini models

Updated: September 2025 • Reading time: 5 minutes • Difficulty: Beginner

Quick Facts: OpenAI API in September 2025

  • Initial credit: New users may receive $5 free trial credits (not guaranteed, many report not receiving them)
  • Minimum deposit: $5 USD
  • Popular model: GPT-4o-mini ($0.00015 per 1K input tokens)
  • Setup time: 5-10 minutes
  • Payment methods: Credit/Debit cards, some regions support local methods

Introduction

To use all the advantages of artificial intelligence, you need to connect an API key from OpenAI.

This guide will walk you through the process of obtaining and configuring your OpenAI API key for use with Vi Voice™ extension.

Whether you're using ChatGPT API for the first time or looking to optimize your existing setup, this comprehensive guide covers everything you need to know about OpenAI API keys, pricing, and best practices.

Registration

First, you need to go to https://platform.openai.com and register.

  1. Click "Sign up" button
  2. Enter your email address
  3. Create a secure password
  4. Verify your email
  5. Complete your profile information
  6. Verify your phone number (required for API access)

Note: OpenAI requires phone verification for all API accounts to prevent abuse. Each phone number can only be used for one OpenAI account.

Create API Key

After registration, in the search bar type "API keys" and select the first result from the search list. Or go directly to this link: https://platform.openai.com/settings/organization/api-keys

Then click "Create new secret key". The name doesn't matter, but most importantly - never show this key to anyone. Our system stores this key in encrypted form, so we from our side cannot see your key. Your key is your property only.

  1. Click "Create new secret key" button
  2. Give it any name (optional) - for example: "Vi Voice Extension"
  3. Copy the key immediately (it won't be shown again)
  4. Save it in a secure place
  5. The key should start with "sk-" prefix

Security tip: Never share your API key publicly or commit it to version control systems like GitHub. Treat it like a password.

Billing Setup

After this, go to Billing. If you cannot find Billing in the menu, then go to this link: https://platform.openai.com/settings/organization/billing/overview

Select a payment method and enter your card details. Attention: we have no access to your card data, all settings are done on the openai.com website.

When adding funds to your account, $10 is sufficient. Based on experience using this extension, this should last for 10-12 months if you use the GPT-4o Mini model. If you want to use the smarter GPT-4o model, then $10 will last you about 1-2 months with active use of the extension.

Important: Since 2024, OpenAI uses a prepaid model. You need to add credits before using the API.

Set Limits

We also recommend setting limits in the Limits menu item. Or via this link: https://platform.openai.com/settings/organization/limits

Setting monthly spending limits helps you control your costs and prevents unexpected charges.

  • Set a reasonable monthly limit (e.g., $5-10)
  • Enable email notifications for usage alerts
  • Monitor your usage regularly in the dashboard
  • Adjust limits based on your actual usage patterns

OpenAI API Pricing Guide (September 2025)

Understanding OpenAI API costs helps you choose the right model for your needs and budget.

Available Models

  • GPT-4o Mini (recommended) - fast and cheap
  • GPT-3.5 Turbo - legacy model, still works but GPT-4o-mini is newer and cheaper
  • GPT-4o - smartest but slower and more expensive

Usage Cost (as of September 2025)

  • GPT-4o Mini: ~$0.00015 per 1K input tokens + $0.0006 per 1K output tokens (roughly $0.001 per 500 words)
  • GPT-3.5 Turbo: ~$0.0005 per 1K input tokens + $0.0015 per 1K output tokens (roughly $0.002 per 500 words)
  • GPT-4o: ~$0.0025 per 1K input tokens + $0.01 per 1K output tokens (roughly $0.02 per 500 words)

Current expenses are displayed in settings (Today / All time)
Prices may change depending on OpenAI conditions (current as of September 2025)

Token calculation: Approximately 750 tokens = 500 words. Most voice input requests use 100-500 tokens.

Cost example: With Vi Voice extension using GPT-4o-mini, processing 100 voice inputs daily would cost approximately $0.10-0.30 per month.

Frequently Asked Questions about OpenAI API Keys

Is OpenAI API key free?
New users sometimes get $5 free credits (expires after 3 months), but this is no longer guaranteed. Most users need to add payment method immediately. After that, you need to add payment method and purchase credits. There's no unlimited free tier.

How much does ChatGPT API cost for Vi Voice users?
GPT-4o-mini costs ~$0.00015 per 1K input tokens. For typical usage with Vi Voice extension, $10 credits last 10-12 months. Heavy users might spend $1-2 monthly.

Can I use the same API key for multiple apps?
Yes, but it's recommended to create separate keys for different applications for better security and usage tracking. You can create up to 100 keys per account.

Where to find my OpenAI API key?
Go to platform.openai.com/api-keys. You can view key names but not the actual keys (they're only shown once when created).

What happens if my API key is leaked?
Immediately delete the compromised key in your OpenAI dashboard and create a new one. Check your usage logs for any unauthorized activity. Set spending limits to prevent unexpected charges.

Can I get OpenAI API key without phone verification?
No, phone verification is mandatory for all OpenAI API accounts. This is a security measure to prevent abuse and fraud.

Do API keys expire?
API keys don't expire automatically, but free credits ($5 trial) expire after 3 months. Your paid credits don't expire as long as your account remains active.

How to check my API usage and costs?
Go to platform.openai.com/usage to see detailed usage statistics, costs breakdown by model, and remaining credits.

What's the difference between GPT-4o and GPT-4o-mini?
GPT-4o-mini is optimized for speed and cost (20x cheaper), perfect for voice transcription. GPT-4o offers better reasoning for complex tasks but costs more and processes slower.

Can I use OpenAI API in my country?
OpenAI API is available in most countries except those under US trade restrictions. Check the official supported countries list for current availability.

Why didn't I receive free credits?
As of 2025, OpenAI no longer guarantees free credits for new accounts. Many users need to add a payment method immediately. The $5 free trial has become inconsistent and may not be available in all regions or for all users.

Enhance Your Voice Input with Vi Voice™ Extension

Now that you have your OpenAI API key, you can unlock the full potential of voice input with Vi Voice™ - the advanced Chrome extension for speech recognition with AI-powered punctuation and grammar correction.

Why Use Vi Voice™ with OpenAI API?

  • AI-Powered Accuracy: Leverage GPT-4o or GPT-4o-mini for intelligent text correction
  • 11 Languages: Full support for English, German, Spanish, French, Italian, Portuguese, Chinese, Japanese, Korean, Russian, and Ukrainian
  • Smart Punctuation: Automatic punctuation and grammar correction in real-time
  • Text Accumulation: Collect up to 5,000 characters (about 750 words) in one session
  • Works Everywhere: Compatible with any website, especially AI chats like ChatGPT, Claude, and others
  • Privacy First: Your API key is encrypted and never shared with anyone

Perfect for AI Chat Users

If you're spending hours typing prompts in ChatGPT, Claude, or other AI assistants, Vi Voice™ transforms your workflow. Simply speak your thoughts, and get perfectly formatted text ready to paste anywhere. Your hands deserve a rest!

Cost-effective: With GPT-4o-mini integration, $10 in API credits typically lasts 10-12 months for average users. That's less than $1 per month for professional-grade voice transcription.

Get Started with Vi Voice™

Ready to revolutionize your text input? Install Vi Voice™ Chrome Extension and start dictating instead of typing. Your productivity will thank you.

Visit Vi Voice™ homepage to learn more about our voice input solution and download the extension for free.

Vi Voice™ | Speak → Get clean text → Done | Your hands deserve a rest!

Join thousands of users who have already discovered the power of voice input with AI enhancement. Whether you're writing emails, creating content, or chatting with AI assistants, Vi Voice™ makes text input effortless.