Frontier LLM API Pricing: A Complete Comparison

The frontier LLM market is moving fast, and so are the price tags. To help you cut through the noise, we've verified current API pricing for six newly released models as of June 2026. This side-by-side comparison shows you exactly what you'll pay per 1 million tokens (MTok) for input, output, cached prompts, and batch processing, along with a blended cost analysis for a typical 3:1 input-to-output query.

All prices are in USD and have been verified against official provider documentation and trusted third-party sources.

Side-by-Side Pricing Table

Model	Provider	Input ($/MTok)	Output ($/MTok)	Cached Input ($/MTok)	Batch Input / Output ($/MTok)	Context Window
Claude Fable 5	Anthropic	$10.00	$50.00	$1.00	$5.00 / $25.00	1M
Claude Opus 4.8	Anthropic	$5.00	$25.00	$0.50	$2.50 / $12.50	1M
GPT-5.5	OpenAI	$5.00	$30.00	$0.50	$2.50 / $15.00	1M
Gemini 3.5 Flash	Google	$1.50	$9.00	$0.15	$0.75 / $4.50	1,048,576 tokens
Grok 4.3	xAI	$1.25	$2.50	$0.20	Not publicly specified	1M
DeepSeek V4 Pro	DeepSeek	$0.44	$0.87	$0.0036	Not publicly specified	1M

Key Details for Each Model

Claude Fable 5

Anthropic's first generally available Mythos-class model launched on June 9, 2026, at a premium price of $10 input and $50 output per million tokens. This is exactly double the cost of Claude Opus 4.8 . The model is free to use on Pro, Max, Team, and Enterprise plans through June 22, 2026, after which metered usage credits will be billed at the API rate .

• Prompt caching: 5-minute cache writes cost $12.50/MTok, and 1-hour writes cost $20/MTok. Cache hits are $1.00/MTok .
• Positioning: Targets agentic coding, vision-heavy workloads, and long-horizon autonomous tasks .

Claude Opus 4.8

Released on May 28, 2026, Opus 4.8 keeps the same $5/$25 pricing as its predecessor Opus 4.7. A new Fast Mode is priced at $10/$50, which is three times cheaper than Opus 4.7's Fast Mode .

• Standard vs. Fast Mode: The $5/$25 standard is for regular workloads. Fast Mode at $10/$50 offers roughly 2.5x faster throughput .
• Context handling: Flat-rate pricing across the full 1M context window .

GPT-5.5

OpenAI launched GPT-5.5 on April 23, 2026, with a significant price increase—doubling the cost of GPT-5.4 to $5 per million input tokens and $30 per million output tokens . A "Pro" variant is also available at $30/$180 .

• Caching: Cached input is priced at $0.50/MTok .
• Context window: Supports up to 1,050,000 tokens with a max output of 128,000 tokens .
• Market reception: The 2x price jump was widely debated among developers .

Gemini 3.5 Flash

Google's latest Flash model went GA on May 19, 2026, at $1.50 input and $9.00 output per million tokens. This makes it approximately 40% cheaper than Gemini 3.1 Pro while delivering stronger coding and reasoning benchmarks .

• Caching: Standard tier cache hits are just $0.15/MTok, with a $1.00/MTok-per-hour storage fee .
• Regional pricing: Non-global endpoints are priced slightly higher at $1.65/$9.90 .
• Batch processing: Available at a 50% discount: $0.75 input / $4.50 output .

Grok 4.3

xAI's flagship model reached general availability on April 30, 2026, with a significant price cut. At $1.25 input and $2.50 output per million tokens, it's roughly 40% cheaper on input and 60% cheaper on output compared to its predecessor Grok 4.20 .

• Caching: Cached input is available at $0.20/MTok .
• Context window: Supports 1 million tokens, though requests exceeding 200K tokens may be billed at a higher tier .
• Reasoning: Features configurable reasoning effort levels (none, low, medium, high) .

DeepSeek V4 Pro

DeepSeek's flagship reasoning model is the undisputed cost leader. Following a permanent 75% price reduction that became official after May 31, 2026, input pricing is just $0.44/MTok and output is $0.87/MTok .

• Caching: Cache hits cost a remarkable $0.0036/MTok, making it highly economical for repetitive prompts .
• Context window: Supports a full 1M tokens with a max output of 384K tokens .

Blended Cost for a Typical Query

To help you compare total costs, we calculated a blended price per 1 million "effective tokens" using a 3:1 input-to-output ratio typical of many production workloads.

Model	Blended Cost per 1M Tokens (3:1 in:out)
DeepSeek V4 Pro	$0.55
Grok 4.3	$1.56
Gemini 3.5 Flash	$3.38
Claude Opus 4.8	$10.00
GPT-5.5	$11.25
Claude Fable 5	$20.00

Choosing the Right Model for Your Budget

• For cost-sensitive, high-volume reasoning tasks: DeepSeek V4 Pro is the clear winner, with a blended cost more than 20x cheaper than premium alternatives.
• For a budget-friendly, general-purpose frontier model: Grok 4.3 offers competitive performance at a very low price.
• For a mid-range workhorse: Gemini 3.5 Flash balances cost and capability, performing well on coding and agent benchmarks.
• For demanding agentic pipelines and complex coding: Claude Opus 4.8 is the strong choice in the premium tier at an effective $10/MTok, while GPT-5.5 is its direct competitor at a slightly higher output price. Claude Fable 5 sits at the top as the most expensive, purpose-built for the most complex, long-horizon autonomous tasks.