Model comparison

Claude Haiku 5.5 vs GLM 5.3

Pricing, context window and real answers (October 2026)

Claude Haiku 5.5 (Anthropic) and GLM 5.3 (Z.ai), 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 5.5z-ai logoGLM 5.3
ProviderAnthropicZ.ai
Input (per 1M tokens)$0.1055$1.48
Output (per 1M tokens)$0.5275$4.65
Typical cost (1,000 in + 500 out tokens × 1,000 calls)$0.3693$3.80
Context window1,000,000 tokens1,048,576 tokens
Release date10/7/20268/18/2026
Input modalitiestext, image, filetext
Throughput (p50)——
Arena · overallUnranked#27 · ELO 1,478
Arena · JapaneseUnranked#34 · ELO 1,454
Arena · codingUnranked#29 · ELO 1,523

Prices are FastMetal's rates, before tax.

Rankings: LMArena leaderboard dataset (lmarena-ai/leaderboard-dataset), CC BY 4.0, snapshot 2026-10-02; category names mapped and ratings rounded by FastMetal.

Which should you pick?

  • On price, Claude Haiku 5.5: $0.5275 per 1M output tokens, 89% less than GLM 5.3.
  • For long documents, GLM 5.3: a 1,048,576-token context window against 1,000,000 for Claude Haiku 5.5.
  • 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 5.5

There are **3** r's in "strawberry." 1. **Spell out the word:** s, t, r, a, w, b, e, r, r, y 2. **Go through each letter and count the r's:** - Position 3: **r** (count = 1) - Position 8: **r** (count = 2) - Position 9: **r** (count = 3) 3. **Check the rest:** s, t, a, w, b, e, and y are not r's. Total: **3**
2.4s200 output tokens

GLM 5.3

# Counting 'r's in "strawberry" **Step 1: Spell out the word letter by letter.** s - t - r - a - w - b - e - r - r - y **Step 2: Go through each letter and mark the 'r's.** | Position | Letter | Is it 'r'? | |----------|--------|------------| | 1 | s | No | | 2 | t | No | | 3 | **r** | ✅ Yes (1st) | | 4 | a | No | | 5 | w | No | | 6 | b | No | | 7 | e | No | | 8 | **r** | ✅ Yes (2nd) | | 9 | **r** | ✅ Yes (3rd) | | 10 | y | No | **Step 3: Tally the results.** - 1st 'r' in "st**r**awberry" - 2nd 'r' in "strawbe**r**ry" - 3rd 'r' in "strawber**r**y" ## Answer: There are **3** 'r's in "strawberry." (Note: two of them appear together in the "rr" near the end, which is easy to miss when c…
5.8s493 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 5.5

The error means `users` is `undefined` when `UserList` renders, so `.map` is called on nothing. The component destructures the `users` prop, but the parent didn't pass it, or passed `undefined`. ## Common causes **1. The parent doesn't pass the prop, or uses a different name** ```jsx <UserList /> // users is undefined <UserList user={users} /> // wrong name: "user" instead of "users" ``` **2. The data hasn't loaded yet (most common with fetched data)** ```jsx function App() { const [users, setUsers] = useState(); // undefined initially useEffect(() => { fetch('/api/users').then(r => r.json()).then(setUsers); }, []); return <UserList users={users} />;…
5.1s888 output tokens

GLM 5.3

## What's happening The error means `users` is `undefined` when the component renders. `undefined` doesn't have a `.map()` method, so JavaScript throws a `TypeError`. Since destructured props that aren't passed default to `undefined`, something upstream isn't providing the value you expect. ## Common causes 1. **The parent doesn't pass the prop, or uses a different name:** ```jsx <UserList /> {/* missing users */} <UserList userList={users} /> {/* prop name mismatch */} ``` 2. **Async data hasn't loaded yet** — the component renders before an API call completes, and the initial value is `undefined`: ```jsx const [users, setUsers] = useState(); // undefin…
17.1s1345 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 5.5

## Issues **Correctness and robustness** 1. **Bare `except:`** catches everything, including `KeyboardInterrupt` and `SystemExit`, so Ctrl+C may not stop the program. Catch specific exceptions: `requests.RequestException` for network problems and `ValueError` for invalid JSON. 2. **Retries non-retryable errors.** A 404 or 401 won't succeed on retry, so retrying wastes time. Only retry transient failures such as 429, 5xx, timeouts, and connection errors. 3. **Sleeps after the final attempt.** The loop sleeps even when no retry follows. 4. **Fixed sleep with no backoff.** Exponential backoff is the standard approach for retries. 5. **Silent failure.** Every failure returns `[]` with no loggin…
18.1s4096 output tokens

GLM 5.3

Here's a breakdown of the issues, followed by a refactored version. ## Readability - **Move imports to module level.** PEP 8 requires top-level imports; importing inside a function hides dependencies and adds overhead on every call (small, but pointless). - **`item["active"] == True`** → just `item.get("active")`. Comparing to `True` with `==` is flagged by PEP 8, and `.get()` avoids a `KeyError` if the key is missing. - **Use a list comprehension** instead of initializing a list and appending in a loop. - **Rename things.** `get_data` doesn't say what it does (`fetch_active_items`?), and `response` beats `r`. Use `_` for the unused loop counter. - **Magic numbers** (`2`, `10`) should be n…
75.0s6434 output tokens

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Frequently asked questions

Which is cheaper, Claude Haiku 5.5 or GLM 5.3?
Per 1M output tokens, Claude Haiku 5.5 is $0.5275 and GLM 5.3 is $4.65 on FastMetal (US dollars, before tax), so Claude Haiku 5.5 is cheaper.
How do the context windows of Claude Haiku 5.5 and GLM 5.3 compare?
Claude Haiku 5.5 takes 1,000,000 tokens; GLM 5.3 takes 1,048,576.
Can I use Claude Haiku 5.5 and GLM 5.3 with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "anthropic-claude-haiku-5-5" or "glm-5.3" 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 5.5 and GLM 5.3 from the browser chat and the API. No monthly fee.

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