Grok 4.5

Grok 4.5 is xAI's Grok 4-generation model for coding, agentic tasks, and knowledge work, sitting below Grok 4.6 in the family.

start building →

compare models

                                                      ..     .
                                                  .:-+-++++--+---:.
                                                 :-=%@@@@@@@%@@%%+.
                                               .:+%@@@@@@@@@@@@%-:
                                              .:+@@@@@@@@@@@@%=-..
                                             .:*@@@@@@@@@@@@@=-:.+-.
                                           ..:=@@@@@@@@@@%%%*-:-==-.
                                           .-=@@@@@@@@@@@%%*::-=%%-..
                                          .+%@@@@@@@@@@@@%+::-=%@%-.
                                        .:+%@@@@@@@@@@@%%+::+%%%@%+.
                                        :*%@@@@@@@@@%@%=-::*%%%@%%-.
                                      .:=@@@@@@@@@@@@@*:::=%%@%%%%-..
                                    ..-=@@@@@@@@@@@@%*:::*%%@@%%%%-.
                                    .-%@@@@@@@@@@@%%*::-=%%@%@%%%%+.
                                   :+%@@@@@@@@@@@%%+:.-=%@@@@@@%%%-.
      .... .  .                   :+%@@@@@@@@@@%%%-..:*%%%%%@%%%%=-.
 .--++++++--+++--..             .:*%@@@@@@@@@@@%=:. ..*%%@%%@%%%%%-.
 .+@@@@@@@@@@@@@%-:.           .:=@@@@@@@%%@@%%*:..  :*%@%%%%%%%%=-.
  :+%@##@##@@@@@@%+:          .:=%@@@@@@@@@@%%*.     :*%%%%%%%%%%=-.
   :+%@@##@##@@@@@%*:.       .-%%@@@@@@@@@@%%+..     :*%%%%%%%%%%=-.
    .-=@@@##@@@@@@@@=:.     .+%%@@@@@@%@%@%%-..     .:*%%%%%%%%%%=-.
     .:=@@#@@#@@@@@@%=-.. .:*%@@@@@@@@@%%%=-.        .+=%%%%%%%%==-.
      .:*%@#@@@@@@@@@@%-..:*%%@@@@@@%%%%%=:..        .*%%%%%%%%%%=-.
        :+@@@@@@@@@@@@@%+::+%@@@@%@@%%%%*:.          :*=%%%%%%%%%=-.
        .:-%@@@@@@@@@@@@%+::+%@@@@@%%%%*:.           :+=%%%%%%====-.
          .-%@@@@@@@@@@@%%*::-=%%%%@%=+:             .*=%%%=%%%==*-.
           .:=%@@@@@@@@@@@%=:::*%%%%%-.             ..+=%%%%%=%===-.
           . :*%@@@@@@@@%@%%=:::*%%=-.               .+=%%=%%%===*-.
              :+%@@@@@@%@@@%@%-.:+*:..              ..*=%=%===%===-.
              ..-%@@@@@@@@%%@%%-:..                  .+=======%==*:.
                .-%%@@%@%%@%%@%=+:                   :+==%%=%=====-.
                .:-=%%@%%@@@%%%%%*:..                .+====%=====*-.
             ..+*-::*%%@%%@%@@@%%%*:.               ..+===========:.
            .:*%%=-::*%%%@%%%%%%%%%*-.              ..+==========*-.
           .:=%@@%=-::+%%%%%%%@@%%%%=-.             ..+==========*-.
          .-=%@@@@%%+:.-=%%%%%%%%%%%%=+.             .+==========*:..
        ..-=%@%@@@@%%+::-*%%%%%%%%%%%==+:           ..+*=======*=*:.
        .+%%%@%@%%@%@%*:.:*=%%%%%%%%%===+:          ..+=========**-.
       :+%%%@%%%@%@%%==:..:+=%%%%%%%%%%%=*:.         .+=========**-
     .:*%%%%@@%%%@%%%*:.  ..+=%%%%%%%=%%%=*:.        .+**==*===***:
    .:=%%%@@%@%%%@%%*:.     .-==%%%%%%%%=%=*-.       .+=*=*==*=***:.
   .-=%@@%%@@@@%%%=*..       .:==%=%%%%=%=%==-.      .-==***=*****:.
  .-%%@@@@%@%%%%%=-.          .:*=%%==%======*-.    ..+**=*******+:.
..+=%%%%%%%%%%%==-.            .:+========*****+..   .-*********++:.
 .:-------------:.              ..::---::-:-:-::.    ..:::::::::::.
  .  . . .                        .  .    .                    .

input · usd / 1m tok

$2.00

output · usd / 1m tok

$6.00

context window

500ktokens

modalities · in → out

pricing

base api ratesusd per 1m tokens

input: $2.00over 200k · $4.00
output: $6.00over 200k · $12.00
cache read: $0.30over 200k · $0.60

brackets are by input tokens per request: a request over a threshold is billed at that bracket's rates for all of its tokens. cache creation can have a separate charge.

providers

xAI hosts Grok 4.5. Impossibl routes your request intelligently and handles failover automatically when a provider is down.

specifications

takes text and image in, gives text outxai/grok-4.5

creatorxAI
model typeText generation
context window500,000 tokens
maximum outputnot published
input
takes text and image in, gives text out
outputtext
tool callingnot verified
releasedjul 8, 2026
endpoint/v1/chat/completions

unknown means the public catalog does not establish that fact. a model's documented capabilities can differ from what a particular api supports. see the model documentation for integration details.

try it · your prompt, this model, live

# responses API
import os
from openai import OpenAI

client = OpenAI(
    api_key=os.environ["IMPOSSIBL_API_KEY"],
    base_url="https://api.impossibl.com/v1",
)

resp = client.responses.create(
    model="xai/grok-4.5",
    input="▌",
)
print(resp.output_text)

edit the prompt, then run

# responses API
import os
from openai import OpenAI

client = OpenAI(
    api_key=os.environ["IMPOSSIBL_API_KEY"],
    base_url="https://api.impossibl.com/v1",
)

resp = client.responses.create(
    model="xai/grok-4.5",
    input="▌",
)
print(resp.output_text)

edit the prompt, then run

benchmarks

intelligence index

38.8#30 of 108 models on the gateway

coding index72.4#17 of 64
agentic index41.2#20 of 53
omniscience25.3#11 of 84
gpqa93.1%#8 of 80
humanity’s last exam42.7%#16 of 87

GPQA93.1%
MMMU-Pro80.4%
AA-LCR79.3%
AutomationBench Partial57.9%
SciCode55.0%
Humanity’s Last Exam42.7%
Tau Banking42.1%
AnalystAgent35.0%
GDP.pdf All-pass18.8%
CritPt15.4%
Multilingual LCR15.0%

Intelligence Index38.81
Omniscience Index25.32
GDPval Elo1385.84
legal index (API)48.2
coding index (API)72.4
agentic index (API)41.2
economics index (API)50
engineering index (API)39.3
intelligence index (API)38.8
strategy and ops index (API)47
finance and accounting index (API)44
healthcare and medical index (API)40.4

view source ↗all source data and breakdowns (json) ↗

each configuration is listed separately; these evaluations describe the tested model configuration, and performance and costs can differ on impossibl. unmeasured scores are omitted and api values keep their source units. last checked 2026-10-14.

compare Grok 4.5 with other models

frontier labs and open weights, best-ranked firstusd / 1m tok · in / out

anthropic/claude-opus-5-5$4.00 / $20.00compare →
openai/gpt-6-astra$10.00 / $50.00compare →
meta/muse-wonder$4.00 / $20.00compare →
xiaomi/mimo-v2.6-pro$0.435 / $0.87compare →

impossibl models --all →

frequently asked questions

What is Grok 4.5?

Grok 4.5 is xAI's Grok 4-generation model for coding, agentic tasks, and knowledge work, sitting below Grok 4.6 in the family. It supports configurable reasoning effort at low, medium, or high, along with tool calling, and xAI serves it from EU-hosted regions.

How much does Grok 4.5 cost?

Grok 4.5 costs $2.00 per million input tokens and $6.00 per million output tokens through the Impossibl API. Cache reads cost $0.30 per million tokens. These base rates apply through 200,000 total input tokens per request. Above 200,000 input tokens, the long-context rates in the pricing table apply to the whole request. All rates are in USD.

view the pricing table ↑

What is the context length of Grok 4.5?

Grok 4.5 has a 500,000-token context window through the Impossibl API.

What inputs and outputs does Grok 4.5 support?

Grok 4.5 accepts text and image as input. Grok 4.5 returns text.

How do I use Grok 4.5 through an API?

Grok 4.5 is available through the Impossibl API. Use xai/grok-4.5 as the model identifier with /v1/chat/completions. The quickstart explains how to create an API key and send your first request.

follow the api quickstart →

When was Grok 4.5 released?

xAI released Grok 4.5 on July 8, 2026.

Creator release announcement ↗

this page describes Grok 4.5 as listed by the impossibl public api. prices and availability come from that catalog, refreshed here every five minutes. this is an impossibl offering, not a comparison of independent hosting-provider quotes. model descriptions and release dates, where available, use the creator sources linked under the answers above.

view the source catalog ↗model as markdown ↗report a correction →