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GLM-5.2 vs Qwen3.8 Max

vs

Which one, when — curated verdict, not a benchmark table

Both are text-out, long-context reasoning models with 131072 max output tokens, so the real split is modality and price: glm-5.2 takes text only at $0.77 input and $2.42 output, while qwen3.8-max also accepts images at $2 input and $6 output, about 2.6x and 2.5x more respectively, with cache reads at $0.25 against $0.143. Pick qwen3.8-max when your pipeline feeds screenshots, charts or scanned pages; pick glm-5.2 for text-only chat, code and tool work, where it is cheaper per token and offers a slightly larger 1000000-token window and the option to disable thinking.

Pricing

GLM-5.2 Qwen3.8 Max Δ
Input / 1M tokens $0.77 $2 0.39×
Output / 1M tokens $2.42 $6 0.4×
Cache read / 1M tokens $0.143 $0.25 0.57×
Cache write 1.25x

Rates from the live catalog at build time; each model page carries the current card.

Where they sit — input price per 1M tokens across all 63 chat models on this billing unit (log scale)

GLM-5.2 · $0.77 Qwen3.8 Max · $2
$0.05 · Qwen3 VL Flash $30 · GPT-5.4 Pro

Capabilities

GLM-5.2 Qwen3.8 Max
Tool use yes yes
Thinking control configurable yes — vendor dial not published
Structured output yes yes
Prompt caching implicit (automatic) implicit + explicit
Cache lifetime not published explicit: 5m, reset on hit
Minimum cached prefix not published 1024 tokens

Specs

GLM-5.2 Qwen3.8 Max
Input modalities text text image
Output modalities text text
Released 2026-06-16 2026-08-03
Context window 1M 984K
Max output 131K 131K
Thinking parameter
  • thinking.type
  • reasoning_effort
Accepted values
thinking.type
  • enabled
  • disabled
reasoning_effort
  • none
  • minimal
  • low
  • medium
  • high
  • xhigh
  • max (none and minimal skip thinking, low and medium map to high, xhigh maps to max)
Default enabled, with reasoning_effort at max: the only GLM with an effort dial, and it defaults to the top of it

Specs are transcribed from each vendor’s documentation; a row a vendor does not publish is left out rather than inferred. Full sources: GLM-5.2 · Qwen3.8 Max

One prompt, both models — measured through the gateway

PROMPT Explain to a CFO, in exactly three sentences, why our LLM bill doubled after we enabled reasoning. CHECK exactly 3 sentences

GLM-5.2 passed · 3 sentences

Enabling reasoning means the LLM now generates thousands of invisible "thinking" tokens to systematically work through complex problems before producing a final answer. Because our cloud providers bill for these internal processing steps at the same rate as standard output, our billable token volume per query has doubled. While this increases our direct API costs, it drastically reduces error rates and manual review labor, ultimately lowering our total cost per resolved transaction.

out 1223 tok (+1138 thinking) latency 17.1 s

Qwen3.8 Max passed · 3 sentences

Enabling reasoning makes the model produce additional hidden steps before responding, and those tokens are billable. It also tends to lengthen each interaction because the model works through more possibilities before settling on an answer. Therefore, the bill doubled mainly due to higher compute and token usage per request, not necessarily because the number of requests doubled.

out 378 tok (+305 thinking) latency 8.6 s

Instruction following (exactly three sentences — countable), audience shaping (CFO register), and the hidden-thinking billing gap the token meters below expose.

PROMPT This function is supposed to return the longest run of consecutive equal items, but callers report it is off by one on single-element inputs and misses runs that end at the last index. Fix it and explain the bug in one paragraph. CHECK fix passes tests

GLM-5.2 missed · 1/8 cases (fails [1])

```python def longest_run(xs): if not xs: return 0 best = 1 cur = 1 for i in range(1, len(xs)): if xs[i] == xs[i - 1]: cur += 1 […]

out 4097 tok (+4036 thinking) latency 58.4 s

Qwen3.8 Max passed · 8/8 cases

```python def longest_run(xs): if not xs: return 0 best = cur = 1 for i in range(1, len(xs)): if xs[i] == xs[i - 1]: cur += 1 else: cur = 1 best = max(best, cur) return best ``` The bug is that the original code starts `best` and `cur` at `0`, so it counts adjacent equal *transitions* rather than the number of items in the run. A run of length `n` has only `n - 1` equal-neighbor transitions, so single-element inputs return `0`, and runs that reach the end are undercounted by one. Initializing the current run to `1` for the first element, resetting it to `1` on a break, and updating `best` from that count fixes the off-by-one.

out 1616 tok (+1411 thinking) latency 34.7 s

Whether the fix is actually correct (runnable), explanation density, and token efficiency on a bounded task.

PROMPT Extract a JSON object with fields {company, quarter, revenue_usd_m, growth_pct, guidance} from this text. Use null for anything not stated; add no other fields. CHECK valid JSON, schema exact

GLM-5.2 passed · 5/5 fields, guidance "withheld"

```json { "company": "Meridian Robotics", "quarter": "September quarter", "revenue_usd_m": 412, "growth_pct": 11, "guidance": "withheld" } ```

out 1947 tok (+1893 thinking) latency 30.9 s

Qwen3.8 Max passed · 5/5 fields, guidance null

{ "company": "Meridian Robotics", "quarter": "September quarter", "revenue_usd_m": 412, "growth_pct": 11, "guidance": null }

out 1199 tok (+1141 thinking) latency 24.4 s

Schema obedience (no invented fields), hallucination pressure (guidance is explicitly withheld), and structured-output path differences.

PROMPT Write a 120-word product announcement for an API gateway feature that caches prompts across providers. Forbidden words: "seamless", "unlock", "game-changer", "revolutionize", "empower". Exactly one sentence must be a question. CHECK 120 words, 0 banned words

GLM-5.2 passed · 120 words, 0 banned, 1 question

We are introducing Caching for our API Gateway, the smartest way to optimize your workflows. Why pay for the exact same response twice? Now, you can automatically store and reuse prompt results across multiple AI providers, drastically reducing latency and overall operational costs. If a user submits a duplicate query, the gateway serves the cached answer instantly, regardless of whether you route to OpenAI, Anthropic, or others. This directly translates to faster applications and significantly lower monthly API bills. You can easily configure your specific caching rules within the developer dashboard and watch your efficiency soar. Stop wasting your valuable tokens on completely redundant computations. Upgrade to the latest gateway version today and experience the future of intelligent prompt management.

out 11125 tok (+10984 thinking) latency 114.8 s

Qwen3.8 Max passed · 120 words, 0 banned, 1 question

Today, our API gateway adds prompt caching across major model providers. It stores prompts and responses in one fast cache layer. Teams can lower token spend, reduce latency, and repeat reliable answers. The feature supports OpenAI, Anthropic, Google, and Mistral through one configuration. You can set retention rules, scope access, and invalidate entries quickly. How does your team maintain consistent results during provider outages? Approved cached responses keep applications stable while fallback routes recover. The dashboard shows hit rates, savings, latency, and provider usage. Engineers receive audit trails for every cached prompt, enabling safer testing. Product managers can compare cost trends before and after cache adoption. Start with a small route, then safely expand caching to production traffic right now.

out 2744 tok (+2591 thinking) latency 46.3 s

Constraint obedience (word budget, banned-word list, the single question), style fingerprint, and length control.

Switch between them with one line

Both ids are in every tab below — the highlighted pair of lines is the only edit. Same endpoint, same key, same request shape.

from openai import OpenAI

client = OpenAI(
    base_url="https://synthorai.io/v1",
    api_key="sk-syn-...",
)

resp = client.chat.completions.create(
    model="glm-5.2",
    # model="qwen3.8-max",  # uncomment this line, comment the one above
    messages=[{"role": "user", "content": "Summarize this diff"}],
    reasoning_effort="medium",
)
print(resp.choices[0].message.content)

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FAQ

Which is cheaper, GLM-5.2 or Qwen3.8 Max?

GLM-5.2 is cheaper on input / 1m tokens ($0.77 vs $2, 2.6× apart). Other rows may point the other way — the table above carries the full card, and real cost depends on your mix.

Can I A/B test GLM-5.2 against Qwen3.8 Max without two integrations?

Yes. Both are served through the same OpenAI-compatible endpoint with one API key — switching is a one-line model-string change, so you can route a fraction of traffic to each and compare bills directly.

Do GLM-5.2 and Qwen3.8 Max support prompt caching?

Yes — both bill cached reads below their input rate, so warm-prefix workloads cost less than the list rates suggest. The exact cache-read rows are in the pricing table above.

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