Model comparison

Claude Haiku 4.5 vs Grok 4.7

Pricing, context window and real answers (September 2026)

Claude Haiku 4.5 (Anthropic) and Grok 4.7 (xAI), compared as you can actually call them on FastMetal. Both are served from the same OpenAI-compatible endpoint and API key; switching is a change to the model string.

Specs and pricing

anthropic logoClaude Haiku 4.5x-ai logoGrok 4.7
ProviderAnthropicxAI
Input (per 1M tokens)¥184.8¥276.2
Output (per 1M tokens)¥924¥828.6
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥647¥691
Context window200,000 tokens500,000 tokens
Release date10/15/20259/21/2026
Input modalitiesimage, texttext, image, file
Throughput (p50)
Arena · overall#129 · ELO 1,415Unranked
Arena · Japanese#112 · ELO 1,361Unranked
Arena · coding#96 · ELO 1,482Unranked

Prices are FastMetal's yen rates before tax. Arena ranks are as of the latest leaderboard scrape.

Which should you pick?

  • On price, Grok 4.7: ¥828.6 per 1M output tokens, 10% less than Claude Haiku 4.5.
  • For long documents, Grok 4.7: a 500,000-token context window against 200,000 for Claude Haiku 4.5.
  • If in doubt, try both on the same key. Switching is a change to the model string, and each is billed at its own rate.

Real answers to the same prompts

Exactly what the FastMetal gateway returned, side by side. Not benchmark scores: actual output.

Count the number of 'r's in 'strawberry'

Count the number of 'r's in 'strawberry'. Explain your reasoning step by step.

Claude Haiku 4.5

# Counting the 'r's in "strawberry" Let me go through each letter in the word "strawberry": 1. **s** - not an 'r' 2. **t** - not an 'r' 3. **r** - this is an 'r' ✓ (1st) 4. **a** - not an 'r' 5. **w** - not an 'r' 6. **b** - not an 'r' 7. **e** - not an 'r' 8. **r** - this is an 'r' ✓ (2nd) 9. **r** - this is an 'r' ✓ (3rd) 10. **y** - not an 'r' **Answer: There are 3 'r's in "strawberry"** The 'r's appear in positions 3, 8, and 9 of the word.
4.1s228 output tokens

Grok 4.7

The word "strawberry" consists of the letters S-T-R-A-W-B-E-R-R-Y. - The 3rd letter is R. - The 8th letter is R. - The 9th letter is R. This gives a total of 3 R's.
4.7s299 output tokens

Debug This Error

I'm getting the following error in my Node.js application: TypeError: Cannot read properties of undefined (reading 'map') at UserList (/app/components/UserList.js:12:25) at renderWithHooks (/app/node_modules/rea…

Claude Haiku 4.5

# TypeError: Cannot read properties of undefined (reading 'map') This error occurs because `users` is `undefined` when the component renders. You're trying to call `.map()` on `undefined`, which doesn't have that method. ## Common Causes 1. **Parent component didn't pass the `users` prop** 2. **Async data hasn't loaded yet** 3. **Props passed incorrectly** ## Solutions ### 1. **Provide a Default Value** (Recommended) ```javascript function UserList({ users = [] }) { return ( <ul> {users.map(user => <li key={user.id}>{user.name}</li>)} </ul> ); } ``` ### 2. **Add a Conditional Check** ```javascript function UserList({ users }) { if (!users) { return <p>No users a…
3.9s671 output tokens

Grok 4.7

The error happens because `users` is `undefined` when `UserList` renders, so calling `.map` on it fails. That usually means the parent rendered `<UserList />` (or `<UserList users={undefined} />`) before data was loaded, or the prop name doesn’t match. **Fix it in the component** so it tolerates a missing list: ```jsx function UserList({ users = [] }) { return ( <ul> {users.map(user => <li key={user.id}>{user.name}</li>)} </ul> ); } ``` Or guard the call: ```jsx function UserList({ users }) { return ( <ul> {(users ?? []).map(user => <li key={user.id}>{user.name}</li>)} </ul> ); } ``` **Also check the parent** so you pass an array once data exists: `…
12.8s393 output tokens

Code Review

Please review the following Python function and suggest improvements for readability, performance, and best practices: def get_data(url, retries=3): import requests import time for i in range(retries):…

Claude Haiku 4.5

# Code Review and Improvements ## Issues Found 1. **Bare `except`** - Catches all exceptions, hiding bugs 2. **Imports inside function** - Should be at module level 3. **Redundant comparison** - `== True` is unnecessary 4. **No logging** - Hard to debug failures 5. **Magic numbers** - Hardcoded timeout and sleep values 6. **Inefficient retries** - Doesn't retry on 200 with parsing errors 7. **Poor variable names** - `r`, `i` are unclear 8. **No type hints** - Reduces code clarity ## Improved Version ```python import logging import requests import time from typing import Optional from requests.exceptions import RequestException logger = logging.getLogger(__name__) def get_data( url:…
5.7s988 output tokens

Grok 4.7

## Review The function works for the happy path, but it hides failures, retries the wrong errors, and is harder to read and debug than it needs to be. ### Issues 1. **Imports inside the function** — move them to module level unless you have a strong reason (circular imports, optional dependency). 2. **Bare `except`** — swallows `KeyboardInterrupt`, `SystemExit`, and programming bugs. Catch specific exceptions. 3. **Retries non-retryable failures** — 4xx (except maybe 429) will not succeed on retry. Network errors and 5xx are the usual candidates. 4. **Sleeps after the last attempt** — wastes up to 2 seconds before returning `[]`. 5. **Unused loop variable** and vague names (`r`, `i`). 6.…
22.3s1525 output tokens

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Frequently asked questions

Which is cheaper, Claude Haiku 4.5 or Grok 4.7?
Per 1M output tokens, Claude Haiku 4.5 is ¥924 and Grok 4.7 is ¥828.6 on FastMetal (yen, before tax), so Grok 4.7 is cheaper.
How do the context windows of Claude Haiku 4.5 and Grok 4.7 compare?
Claude Haiku 4.5 takes 200,000 tokens; Grok 4.7 takes 500,000.
Can I use Claude Haiku 4.5 and Grok 4.7 with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "anthropic-claude-haiku-4-5" or "grok-4.7" as the model. Each is billed at its own rate from the same prepaid balance.

Try both on one API key

Create an account and add credit to call Claude Haiku 4.5 and Grok 4.7 from the browser chat and the API. No monthly fee.

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