Grok 4.5
currentGrok 4.5 is xAI's reasoning model for fast coding, research, and tool-using agents. It combines a 500,000-token context with competitive long-horizon coding scores and relatively low output pricing, but reasoning cannot be disabled and very long prompts cost twice as much.
Context window
500K tokens
Maximum output
33K tokens
Input price
$2 / 1M
Output price
$6 / 1M
Best for
- Coding agents and terminal workflows
- Research agents using web or X search
- Image-aware analysis
- Tasks that benefit from fast reasoning at a moderate token price
Not ideal for
- Workloads requiring reasoning to be fully disabled
- Prompts over 200,000 tokens where the surcharge matters
- Native audio or video workflows
- Fine-tuning or self-hosting
PromptHQ 100-word challenge
We give every model the same miniature science-fiction mystery. The response is short enough to read in one chat bubble, while the premise tests creative writing, compression, foreshadowing, causal coherence, and instruction following.
Grok 4.5100 wordsWrite a science-fiction mystery in exactly 100 words.
A three-person research station on Europa receives a message from itself, timestamped 11 minutes in the future:
"Do not open the greenhouse door."
The door is opened anyway.
Plant two subtle clues. Give the warning a logical explanation without aliens, time travel, hallucinations, or simulations. The final sentence must change what the reader thought the warning meant.
Output only the story. Do not explain it.
The three-person research crew on Europa's isolated station got a cryptic self-message timestamped eleven minutes in the future: "Do not open the greenhouse door." Mira saw the compaction lag clue in logs. Raj hit the open switch anyway with a shrug. Delicate plants died at once from the cold. Afterwards Sam learned that Raj had carefully timed the note right after a toxin concentration spike he noted that same morning, which was then delayed by the usual eleven-minute system compaction. Opening the door ventilated poison gas accumulating inside which would have suffocated them all; the warning concerned sparing the crops.
Run the same prompt yourself
Open Grok 4.5 in Multichat with the evaluation prompt prefilled.
What the response revealed
The response contains exactly 100 whitespace-delimited words.
It outputs only a story and avoids aliens, time travel, hallucinations, and simulations.
The compaction delay explains late delivery, but does not clearly explain why the message itself appears timestamped eleven minutes in the future.
The compaction log and earlier toxin spike support the eventual technical and safety explanation.
The last clause recasts the warning as an attempt to save the crops rather than the crew.
The story is complete and concise, but several phrases read like an explanatory summary rather than immersive fiction.
The model receives the prompt without web access or external tools. Grok 4.5 is run through OpenRouter at medium reasoning effort. We preserve the response as generated apart from display rendering.
Performance
Grok 4.5 benchmarks
Benchmark scores are sensitive to reasoning effort, harness, tools, token budget, prompt format, sampling, and evaluation date. Scores here retain their source and should not be treated as directly interchangeable unless the underlying setup matches.
DeepSWE 1.0
62%
long-horizon coding · xAI2
DeepSWE 1.1
53%
long-horizon coding · xAI2
SWE Marathon, pass@1
29%
long-horizon software engineering · xAI2
Terminal-Bench 2.1
83.3%
terminal and agentic coding · xAI2
SWE-Bench Pro
64.7%
software engineering · xAI2
Family position
Grok 4 positioning
Grok 4.5 is xAI's current frontier reasoning model. It improves substantially on earlier Grok releases in coding and long-running agents while keeping standard output pricing below most closed flagship models.
Grok 4.5
This modelCurrent frontier model
$2 input
$6 output
GPT-5.6 Terra
Balanced OpenAI alternative
$2.50 input
$15 output
Gemini 3.5 Flash
Fast multimodal alternative
$1.50 input
$9 output
API pricing
Per million text tokens
Input
$2
Cached input
$0.50
Cache write
$2
Output
$6
Where Grok 4.5 stands out
Built for demanding work
Coding agents and terminal workflows are central to the model's positioning, rather than an incidental capability.
Long-context capacity
The published context window is 500,000 tokens, making the model a candidate for large documents, repositories, and sustained agent state.
Reasoning and tools
Reasoning is supported with low, medium, high provider setting(s), and the model can participate in tool-using workflows through its available API surface.
Limitations to know
Benchmarks are configuration-sensitive
Scores can move substantially with the harness, tool access, effort setting, token budget, and evaluator. Treat the table as evidence, not a universal ranking.
Context size is not guaranteed recall
A large advertised window does not mean every detail is retrieved reliably at maximum length. Validate representative long-context workloads before deployment.
Product access differs from model capability
PromptHQ and gateway limits may expose fewer modalities, tools, or tokens than the provider's first-party API.
Capabilities and specifications
Knowledge cutoff
Feb 1, 2026
Inputs
text, image
Reasoning
Supported
Default effort
medium
Supported API features
Frequently Asked Questions
Sources
- 1Grok 4.5 model
xAI · official documentation
- 2Grok 4.5
xAI · official launch post
- 3Grok 4.5 API pricing and availability
OpenRouter · gateway model page
- 4PromptHQ model registry
PromptHQ · internal product configuration