Language Model News

2026/10/13

  1. How much does speech-to-text cost per hour? Comparing the xAI and Mistral APIs
  2. Mistral Large 4 costs $1.36 in and $4.18 out, at half price for two weeks after launch
  3. Claude Managed Agents' web_fetch now fetches only URLs that already appear in the session
  4. xAI's speech-to-text API costs $0.10 an hour in batch, and moved to 2.0 on 2 October
  5. Claude Max and Team plans now include monthly API credits ($100 on Max 5x)
  6. GPT-6.1 Sol charges less than GPT-6 Sol for cached input
  7. Claude Sonnet 5.5 keeps Sonnet 5's price, and its cache reads were halved on 7 October
  8. Claude Haiku 5.5 is priced like GPT-6 Luna up to 100K tokens, and five times higher beyond

2026/09/29

  1. Gemini 2.5 models are now limited to users who have used them before
  2. Grok 4.7 joins xAI's model list at the same price and context as Grok 4.6
  3. Gemini 3.8 Live pricing: audio in at $0.005 a minute and audio out at $0.018

2026/09/28

  1. Gemini 3.8 Flash TTS and Flash-Lite TTS prices double on 1 January 2027
  2. Claude Opus 5.5 is $4 in and $20 out, and the model Anthropic now recommends first
  3. GPT-6 Sol and GPT-6 Luna: Luna costs a twentieth of Sol

2026/09/15

  1. DeepSeek V4.1 Flash takes over from V4 Flash at a lower price
  2. Sakana AI's Fugu Ultra v2 and Fugu Max answer by routing work to other models
  3. Cognition's SWE-2 is a coding model built on Kimi K3
  4. Inception's Mercury 2.5, a diffusion model at $0.75 per million output tokens
  5. GPT-Live 1 bills by the minute, at $0.05, with the reasoning model on top

2026/09/08

  1. Meta sells the same model at two prices, and the cheap one is paid for with your prompts
  2. Grok 4.6 is the flagship, and it holds half the context of Grok 4.3
  3. Kimi K3 holds a million tokens at one flat rate
  4. The same Qwen model costs less from Beijing than from Singapore
  5. On Mistral, Large costs a third of Medium
  6. GPT-6 Astra and the three models that make up GPT-6
  7. GPT-6 Astra prices, and the 272K line that reprices the whole request
  8. Claude Fable 5.1 takes the top of the lineup, and Fable 5 moves to legacy
  9. Cache reads on Fable 5.1 are a quarter of what they cost on Fable 5

2026/09/02

  1. The current Claude lineup: 1M context, 128K output, retirement more than a year out
  2. SWE-bench Verified is at 97, and the top of the table is hard to read
  3. A benchmark number means nothing without the conditions it was taken under
  4. Claude API prices, and the Sonnet 5 increase that did not happen
  5. OpenAI API prices: the GPT-5.6 line has long-context rates too
  6. Gemini API prices, and the two dates that change them
  7. DeepSeek now charges double during peak hours
  8. Perplexity Sonar ends on 27 September 2026, replaced by the Agent API
  9. What prompt caching actually costs, and where the tenth does not hold
  10. Long context: who reprices the whole request, and who does not
  11. Adding an MCP server to Claude Code, and which scope to pick

GPT-6 Sol and GPT-6 Luna: Luna costs a twentieth of Sol

OpenAI released GPT-6 Sol and GPT-6 Luna on 22 September 2026⁠[1]. The model ids are gpt-6-sol and gpt-6-luna, and both are available through the Responses and Chat Completions APIs⁠[1].

Both are reasoning models, with text and image input and text output⁠[2,3]. OpenAI describes Sol as built to power complex coding and agentic workflows, and Luna as its most efficient model for focused, high-volume tasks⁠[2,3].

The context window is 1,050,000 tokens on both⁠[2,3]. Of that, input can take up to 922,000 tokens, and one response can run to 128,000⁠[2,3].

The knowledge cutoff is 20 April 2026 for Sol and 18 May 2026 for Luna, so the cheaper model is about a month more recent⁠[2,3].

Per million tokens, Sol is $2 input, $0.20 cached input and $10 output⁠[2]. Luna is $0.10, $0.01 and $0.50, exactly a twentieth of Sol on every rate⁠[2,3].

A cache write is 1.25 times the input rate, which comes to $2.50 on Sol and $0.125 on Luna⁠[2,3].

Prompts with more than 272K input tokens are billed at twice the input and cache rates⁠[2,3]. Batch and Flex are half the standard rates, and Fast mode is twice the applicable rates⁠[2,3].

Both also work with the Batch API, and support streaming, structured outputs, function calling, web search and prompt caching⁠[2,3].

A bug in image encoding had degraded image understanding in Sol and Luna⁠[1]. The changelog records it as fixed on 25 September⁠[1].

Sources

  1. OpenAI - Changelog
  2. OpenAI - GPT-6 Sol model
  3. OpenAI - GPT-6 Luna model