GLM-4.7 Flash Heretic vs GLM-5.3 Flash. Price and specs.

For 10,000 requests of 2,000 tokens in and 500 out, GLM-5.3 Flash costs 29% less than GLM-4.7 Flash Heretic on Zurelay: $2.11 against $2.97. Both are below their labs' list prices: 13% for GLM-4.7 Flash Heretic and 62% for GLM-5.3 Flash.

Try both with one keySee the specs

Side by side

Specs and prices. Live.

GLM-4.7 Flash Heretic and GLM-5.3 Flash side by side
GLM-4.7 Flash HereticGLM-5.3 Flash
LabZ.aiZ.ai
Released—Aug 26, 2026
Context window200K tokens1M tokens
Max output24K tokens128K tokens
ReadsTextText
Reasoning levelsnone, low, medium, highlow, high, max
Price per 1M, in / out$0.061 / $0.35$0.058 / $0.19
Lab list price$0.07 / $0.40$0.15 / $0.50
Cached input per 1M$0.0305$0.0116
10K typical requests$2.97$2.11

Prices in US dollars per 1M tokens on Zurelay, live from the catalog. A typical request is 2,000 tokens in and 500 out. Output limits are each lab's.

What they're for

As each lab describes it.

GLM-4.7 Flash Heretic

GLM-4.7 Flash Heretic is a community uncensored version of Z.ai's GLM-4.7 Flash, made with Heretic, an open-source tool that removes a model's refusals automatically. It isn't made or endorsed by Z.ai. The Zurelay GLM-4.7 Flash Heretic API serves it through one OpenAI-compatible endpoint with a 200K-token context window, reasoning you can switch off and tool calling, at 13% below list price. Zurelay's Terms of Service still apply to everything you send it.

  • Uncensored agents
  • Testing your own AI systems
  • Fiction and roleplay
GLM-4.7 Flash Heretic API

GLM-5.3 Flash

GLM-5.3 Flash is Z.ai's low-cost GLM, with 18B of its 320B parameters active per token. Z.ai says it outperforms GLM-5.2 and approaches Claude Opus 4.8 on coding and agent benchmarks. The Zurelay GLM-5.3 Flash API serves it through one OpenAI-compatible endpoint with a 1M-token context window, at 62% below Z.ai's list price.

  • Coding agents on a budget
  • Frontend and game code
  • Office and finance work
GLM-5.3 Flash API

Try both

Test on your own prompts.

Specs don't say which model handles your work better. Send the same requests to both and compare the answers, the tokens and the bill. On Zurelay that's a change of model name.

To price a whole month, use the LLM cost calculator.

compare.py
from openai import OpenAI
client = OpenAI(base_url="https://api.zurelay.com/v1", api_key="YOUR_ZURELAY_KEY")
prompt = [{"role": "user", "content": "Summarize this contract: ..."}]
# Same key, same code: only the model name changes
for model in ["glm-4.7-flash-heretic", "glm-5.3-flash"]:
    reply = client.chat.completions.create(model=model, messages=prompt)
    print(model, reply.usage.total_tokens, reply.choices[0].message.content[:200])

FAQ

GLM-4.7 Flash Heretic vs GLM-5.3 Flash questions.

Anything else? Ask our team and we’ll answer by email.

Is GLM-4.7 Flash Heretic or GLM-5.3 Flash cheaper?

For 10,000 requests of 2,000 tokens in and 500 out, GLM-5.3 Flash costs 29% less than GLM-4.7 Flash Heretic on Zurelay: $2.11 against $2.97. Per 1M tokens, GLM-4.7 Flash Heretic is $0.061 input and $0.35 output, and GLM-5.3 Flash is $0.058 and $0.19.

Which has the bigger context window?

GLM-5.3 Flash, at 1M tokens, against 200K for GLM-4.7 Flash Heretic.

Can I use GLM-4.7 Flash Heretic and GLM-5.3 Flash with one API key?

Yes. One Zurelay key calls both. With an OpenAI SDK, point it at https://api.zurelay.com/v1 and change only the model name, glm-4.7-flash-heretic or glm-5.3-flash, to switch.

Are these the real models?

Yes. Each model is served over several routes run by independent sellers, and every route is tested before it serves requests and every day after, with identity, dated-knowledge and reasoning checks that catch an older or different model sold under the name you asked for.

More pricing

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