Step-3.7-Flash vs GLM 5.3 Flash

Practical read: GLM 5.3 Flash costs about a fifth as much and reads four times more context. One API key runs both.

No card required. Start with 1 million free tokens.

Side by side:

StepFun: Step-3.7-Flash compared with Z.ai: GLM 5.3 Flash
Attribute	Step-3.7-Flash `stepfun-ai/step-3.7-flash`	GLM 5.3 Flash `z-ai/glm-5.3-flash`
Price, 1M in + out	$1.42 Featherless AI, cheapest route	$0.26 Wafer, cheapest route
Best for		Low cost and long documents
Input / output, 1M	$0.21 / $1.21	$0.053 / $0.21
Cached input	Not published	$0.015825/1M to $0.079125/1M
Context window	256K 256,000 tokens	1.05M 1,048,576 tokens
First token, p50	Measuring	0.72 s via FriendliAI
AI IQ	IQ 103 #113 on AI IQ	IQ 119 #50 on AI IQ
Provider routes	1	32 with failover
Privacy	Zero retention route	Confidential E2EE and zero retention route
Recent route uptime range	not enough data	0.00% to 100.00%
Publisher	StepFun	Z.AI
Modes	chat	chat
More detail	Overview	Overview Pricing Providers

Price adds one million input and one million output tokens on the cheapest route. Prices and speed change: see the monthly reports and run a small eval before you choose a default.

Test both with your agent

Paste this into Claude Code, Cursor or any coding agent.

Compare Step-3.7-Flash and GLM 5.3 Flash in this project through TrustedRouter.

1. Read https://trustedrouter.com/docs/llms.txt
2. Point the OpenAI-compatible client at
   https://api.trustedrouter.com/v1 and read the key from
   TRUSTEDROUTER_API_KEY.
3. Run our eval prompts on stepfun-ai/step-3.7-flash, then on z-ai/glm-5.3-flash.
4. Show me cost, latency and quality side by side before changing the default.

import os
from openai import OpenAI

client = OpenAI(
    base_url="https://api.trustedrouter.com/v1",
    api_key=os.environ["TRUSTEDROUTER_API_KEY"],
)
for model in ("stepfun-ai/step-3.7-flash", "z-ai/glm-5.3-flash"):
    response = client.chat.completions.create(
        model=model,
        messages=[{"role": "user", "content": "What is the capital of France?"}],
    )
    print(model, response.choices[0].message.content)

for model in stepfun-ai/step-3.7-flash z-ai/glm-5.3-flash; do
  curl https://api.trustedrouter.com/v1/chat/completions \
    -H "Authorization: Bearer $TRUSTEDROUTER_API_KEY" \
    -H "Content-Type: application/json" \
    -d "{\"model\": \"$model\", \"messages\": [{\"role\": \"user\", \"content\": \"What is the capital of France?\"}]}"
done

Your agent will need an API key.

Questions

Which should I use, StepFun: Step-3.7-Flash or Z.ai: GLM 5.3 Flash?

Z.ai: GLM 5.3 Flash has the lower published input-plus-output rate, more Credits provider routes and the larger context window. There is not enough recent probe data to compare speed.

Is StepFun: Step-3.7-Flash or Z.ai: GLM 5.3 Flash cheaper?

The current cheapest TrustedRouter route is $1.42425/1M for StepFun: Step-3.7-Flash and $0.26375/1M for Z.ai: GLM 5.3 Flash. The comparison uses current catalog prices and updates as provider pricing changes.

Is StepFun: Step-3.7-Flash or Z.ai: GLM 5.3 Flash faster?

Current measured p50 time to first token is not enough data for StepFun: Step-3.7-Flash and 719 ms for Z.ai: GLM 5.3 Flash. These are routed probe measurements, not vendor-advertised speeds, and update as new samples arrive.

Can I test StepFun: Step-3.7-Flash and Z.ai: GLM 5.3 Flash with the same API?

Yes. Use the same OpenAI-compatible TrustedRouter base URL and API key, then change only the model id between stepfun-ai/step-3.7-flash and z-ai/glm-5.3-flash. This makes side-by-side evals possible without maintaining two provider integrations.

More comparisons

All comparisons

Try Step-3.7-Flash and GLM 5.3 Flash with one key.

TrustedRouter is useful when you know the model you want, but still need provider rollover, budget limits, usage records, and a prompt path you can verify.

No card required. Start with 1 million free tokens.