Gemini Omni 1.2 Flash vs GLM 5.3

As of November 12, 2026, Gemini Omni 1.2 Flash costs 7% more per input token than GLM 5.3 ($1.50 vs $1.40 per 1M) and has a 128K-token context window versus 1M.

Prices from LiteLLM's price fileChecked November 12, 2026

Gemini Omni 1.2 Flash vs GLM 5.3 side by side

Headline prices in US dollars per 1M tokens: each model's own lab where it sells it, otherwise its cheapest provider. Source: LiteLLM model price file, as of November 12, 2026.
	Gemini Omni 1.2 Flash	GLM 5.3
Input, per 1M tokens	$1.50	$1.40
Output, per 1M tokens	$9.00	$4.40
Cache read, per 1M tokens	–	$0.26
Cache write, per 1M tokens	–	$0
Context window	131,072 tokens	1,000,000 tokens
Max output	65,536 tokens	128,000 tokens
Image input	Yes	Yes
Tool calling	–	Yes
Structured output (JSON)	–	Yes
Prompt caching	–	Yes
Reasoning	Yes	Yes
Providers on LiteLLM	2	25
Price shown is from	Google AI Studio	Z.ai
Added to LiteLLM	November 5, 2026	August 27, 2026

Cheapest provider for each

Gemini Omni 1.2 Flash: Google AI Studio at $1.50 input and $9.00 output per 1M tokens (gemini/gemini-omni-1.2-flash)
GLM 5.3: CLF AI Gateway at $0.56 input and $1.76 output per 1M tokens (clf_ai_gateway/glm-5.3)

When to pick which

Pick GLM 5.3 for

Costs 7% less per input token: $1.40 vs $1.50 per 1M.
Larger context window: 1,000,000 vs 131,072 tokens.

From differences in the data above only; where the data is equal, no reason is given.

Call Gemini Omni 1.2 Flash or GLM 5.3 with LiteLLM

Both use the OpenAI format through LiteLLM, so switching is a model name change. Set each provider's API key in the environment first.

Python SDK

from litellm import completion

messages = [{"role": "user", "content": "Hello!"}]

# Gemini Omni 1.2 Flash
response = completion(model="gemini/gemini-omni-1.2-flash", messages=messages)

# GLM 5.3
response = completion(model="zai/glm-5.3", messages=messages)

# Gemini Omni 1.2 Flash, falling back to GLM 5.3 if the call fails
response = completion(model="gemini/gemini-omni-1.2-flash", messages=messages, fallbacks=["zai/glm-5.3"])

FAQ

Which is cheaper, Gemini Omni 1.2 Flash or GLM 5.3?

GLM 5.3 is cheaper at 3 input tokens per output token: $2.15 per 1M tokens blended ($1.40 input, $4.40 output), versus $3.375 ($1.50 and $9.00) for Gemini Omni 1.2 Flash, as of November 12, 2026.

Which has the larger context window, Gemini Omni 1.2 Flash or GLM 5.3?

GLM 5.3 has the larger context window: 1,000,000 tokens, versus 131,072 for Gemini Omni 1.2 Flash.

Can I switch from Gemini Omni 1.2 Flash to GLM 5.3 without changing my code?

Yes. Through LiteLLM both use the OpenAI format, so switching means changing the model name from "gemini/gemini-omni-1.2-flash" to "zai/glm-5.3", or pointing a LiteLLM gateway model alias at the other model. You can also use one as a fallback for the other.