# Grok 4 API Rate Limits, Pricing & Performance (July 2026) - Tool: AI API Limits & Performance Matrix - Last updated: July 2026 ## TL;DR Grok 4 was retired on May 15, 2026. Deprecated slugs now redirect to Grok 4.3 billing; xAI's current flagship is Grok 4.5 (launched July 8, 2026). Below are Grok 4.5 limits: 150 RPS / 50M TPM on production tiers, 500K-token context, $2.00 input / $6.00 output per MTok with cached input at $0.50/MTok (75% off). No free API tier. EU access expected mid-July 2026. ## Frequently asked questions ### Is Grok 4 still available via the API? No. Grok 4 was retired on May 15, 2026. The deprecated grok-4 slug redirects to Grok 4.3 billing, which has itself been superseded by Grok 4.5 (launched July 8, 2026). If you are calling grok-4 in production, update your model string to the current Grok 4.5 API name — verify the exact string on docs.x.ai. ### How do I increase my Grok 4.5 rate limits? Tiers unlock automatically as your cumulative API spend (since January 1, 2026) crosses thresholds — no manual request needed for standard tier advances. To go beyond default caps (150 RPS / 50M TPM), submit the rate-limit increase request form on the xAI Console at docs.x.ai. For Voice or Imagine endpoints, contact sales@x.ai directly. ### Is the Grok 4.5 API free? No. xAI ended its $150/month free credit program in May 2025. There is no free API tier for Grok 4.5. You must recharge your xAI account to access the API; billing starts at $2.00/MTok input and $6.00/MTok output. ### How does Grok 4.5 pricing compare to GPT-5 and Claude Opus? Grok 4.5 is significantly cheaper on output: $6.00/MTok vs GPT-5.5's $30.00/MTok (5× cheaper) and Claude Opus 4.8's $25.00/MTok (4× cheaper). Input is $2.00/MTok vs $5.00 for both rivals. Grok 4.5 does not offer a batch discount at launch, while both GPT-5.5 and Opus 4.8 offer 50% off for batch. For teams outside the EU, the lack of EU endpoints as of July 10, 2026 is a constraint. ### What does the HTTP 429 error mean on the xAI API? HTTP 429 Too Many Requests means you have exceeded either the hard RPS cap (150 requests/second for Grok 4.5) or the TPM cap (50M tokens/minute). The OpenAI-compatible SDK raises this as RateLimitError. xAI does not send a Retry-After header, so implement exponential backoff unconditionally: wait 2^attempt seconds between retries, with random jitter to avoid thundering-herd. ### Does Grok 4.5 support prompt caching? Yes. Cached input is priced at $0.50/MTok — a 75% discount off the $2.00 standard input rate. Cache stable system context, instructions, and retrieved documents to cut costs dramatically in agentic loops. Note: requests using more than 200K tokens may bill at a higher unpublished rate; keep prompts under 200K where possible. ### Is Grok 4.5 available in the EU? Not as of July 10, 2026. xAI announced EU API access for Grok 4.5 for mid-July 2026, but it was not available at launch. EU teams should monitor docs.x.ai for the availability update. If EU data residency is a hard requirement, consider Claude Opus 4.8 or GPT-5.5, both of which have EU endpoints available now. ### Can RapidDev help us optimize Grok 4.5 API costs and quota? Yes. RapidDev specializes in gateway architecture, caching strategies, and quota engineering for AI APIs including xAI. If you need help reducing your Grok 4.5 spend or avoiding 429 cascades in production, book a free scoping call at rapidevelopers.com/contact. --- Source: https://www.rapidevelopers.com/ai-api-limits-performance-matrix/grok-4 © RapidDev — https://www.rapidevelopers.com/ai-api-limits-performance-matrix/grok-4