Claude Haiku 5.5 vs Grok 4 Fast
Claude Haiku 5.5 leads the LLM Stats Score 49.9 to 31.2. Claude Haiku 5.5 is 1.4x cheaper per token.
Anthropic · xAI · Updated for 2026
Which is better?
Claude Haiku 5.5 leads the overall LLM Stats Score 49.9 to 31.2, ranking #20 overall.
On price, Claude Haiku 5.5 is roughly 1.4x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Grok 4 Fast also accepts a larger context window (2,000,000 input tokens), making it the stronger choice for long documents and large codebases.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose Claude Haiku 5.5
- overall performance matters — it scores 49.9 and ranks #20 on LLM Stats
- your work emphasizes reasoning and coding — it leads those capability indexes
- cost matters — it's about 1.4x cheaper per token
- you want the most recent training data — it shipped Oct 2026
Choose Grok 4 Fast
- you process long inputs — it offers a 2,000,000 token context window
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
36 reported for Claude Haiku 5.5 · 7 for Grok 4 Fast
Claude Haiku 5.5 and Grok 4 Fastdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Claude Haiku 5.5 ($0.10/1M tokens) is 2.0x cheaper than Grok 4 Fast ($0.20/1M tokens).
For output processing, Claude Haiku 5.5 ($0.50/1M tokens) costs the same as Grok 4 Fast ($0.50/1M tokens).
In conclusion, Grok 4 Fast is more expensive than Claude Haiku 5.5.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Grok 4 Fast accepts 2,000,000 input tokens compared to Claude Haiku 5.5's 1,000,000 tokens. Claude Haiku 5.5 can generate longer responses up to 128,000 tokens, while Grok 4 Fast is limited to 30,000 tokens.
Input capabilities
Documented input modalities across available providers
Both Claude Haiku 5.5 and Grok 4 Fast support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Claude Haiku 5.5
Grok 4 Fast
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
Claude Haiku 5.5 was released on 2026-10-07, while Grok 4 Fast was released on 2025-08-28.
Claude Haiku 5.5 is 14 months newer than Grok 4 Fast.
Oct 7, 2026
2 weeks ago
1.1yr newerAug 28, 2025
1.2 years ago
Knowledge Cutoff
When training data ends
Claude Haiku 5.5 has a documented knowledge cutoff of 2026-06-01, while Grok 4 Fast's cutoff date is not specified.
We can confirm Claude Haiku 5.5's training data extends to 2026-06-01, but cannot make a direct comparison without Grok 4 Fast's cutoff date.
Jun 2026
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Provider Availability
Claude Haiku 5.5 is available from Anthropic. Grok 4 Fast is available from xAI.
Claude Haiku 5.5
Grok 4 Fast
Outputs Comparison
Judge for yourself.
Run your own prompts against Claude Haiku 5.5 and Grok 4 Fast side-by-side, then vote on the output you prefer.
FAQ
Common questions about Claude Haiku 5.5 vs Grok 4 Fast.