DeepSeek V4.1 Flash vs GLM 5.3 Flash (Fortanix)

Practical read: DeepSeek V4.1 Flash reads eight times more context. GLM 5.3 Flash (Fortanix) costs about an eighth as much. One API key runs both.

No card required. Start with 1 million free tokens.

Side by side:

DeepSeek: DeepSeek V4.1 Flash compared with GLM 5.3 Flash (Fortanix)
Attribute	DeepSeek V4.1 Flash `deepseek/deepseek-v4.1-flash`	GLM 5.3 Flash (Fortanix) `fortanix/glm-5.3-flash`
Price, 1M in + out	$0.16 Engy, cheapest route	$0.02 Fortanix, cheapest route
Best for	Long documents	Low cost
Input / output, 1M	$0.032 / $0.13	$0.01 / $0.01
Cached input	$0.01/1M to $0.165108/1M	Not published
Context window	1.05M 1,048,576 tokens	131K 131,072 tokens
AI IQ	IQ 126 #24 on AI IQ	IQ 119 #50 on AI IQ
Provider routes	21 with failover	1
Privacy	Confidential E2EE and zero retention route	Zero retention route
Publisher	DeepSeek	fortanix
Modes	chat decide	chat
More detail	Overview Pricing Providers	Overview

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 DeepSeek V4.1 Flash and GLM 5.3 Flash (Fortanix) in this project through TrustedRouter.

1. Read https://trustedrouter.com/docs/llms.txt
2. Point the OpenAI-compatible client at
   https://api-azure.trustedrouter.com/v1 and read the key from
   TRUSTEDROUTER_API_KEY.
3. Run our eval prompts on deepseek/deepseek-v4.1-flash, then on fortanix/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-azure.trustedrouter.com/v1",
    api_key=os.environ["TRUSTEDROUTER_API_KEY"],
)
for model in ("deepseek/deepseek-v4.1-flash", "fortanix/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 deepseek/deepseek-v4.1-flash fortanix/glm-5.3-flash; do
  curl https://api-azure.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, DeepSeek: DeepSeek V4.1 Flash or GLM 5.3 Flash (Fortanix)?

DeepSeek V4.1 Flash has more Credits provider routes and the larger context window. GLM 5.3 Flash (Fortanix) has the lower published input-plus-output rate. There is not enough recent probe data to compare speed.

Is DeepSeek: DeepSeek V4.1 Flash or GLM 5.3 Flash (Fortanix) cheaper?

The current cheapest TrustedRouter route is $0.15825/1M for DeepSeek: DeepSeek V4.1 Flash and $0.02/1M for GLM 5.3 Flash (Fortanix). The comparison uses current catalog prices and updates as provider pricing changes.

Can I test DeepSeek: DeepSeek V4.1 Flash and GLM 5.3 Flash (Fortanix) with the same API?

Yes. Use the same OpenAI-compatible TrustedRouter base URL and API key, then change only the model id between deepseek/deepseek-v4.1-flash and fortanix/glm-5.3-flash. This makes side-by-side evals possible without maintaining two provider integrations.

More comparisons

All comparisons

Try DeepSeek V4.1 Flash and GLM 5.3 Flash (Fortanix) 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.