Which is cheaper, Gemini 3.8 Flash and GLM-5.3-Flash?

GLM-5.3-Flash has the lowest input price. Per 1M input tokens: Gemini 3.8 Flash from $0.75 and GLM-5.3-Flash from $0.07.

Which has the larger context window, Gemini 3.8 Flash and GLM-5.3-Flash?

GLM-5.3-Flash has the largest context window: Gemini 3.8 Flash 1,048,576 tokens and GLM-5.3-Flash 1,310,720 tokens.

Which is better for coding, Gemini 3.8 Flash and GLM-5.3-Flash?

Gemini 3.8 Flash scores highest on the Artificial Analysis Coding Index: Gemini 3.8 Flash 76.3 and GLM-5.3-Flash 71.5.

Which is smarter, Gemini 3.8 Flash and GLM-5.3-Flash?

GLM-5.3-Flash scores highest on the Artificial Analysis Intelligence Index: Gemini 3.8 Flash 40.9 and GLM-5.3-Flash 41.8.

Can I switch between Gemini 3.8 Flash and GLM-5.3-Flash without changing my code?

Yes. All of them are served through FastRouter's OpenAI-compatible API, so switching is a change of the model parameter (google/gemini-3.8-flash, z-ai/glm-5.3-flash).

Gemini 3.8 Flash vs GLM-5.3-Flash

Side-by-side pricing per provider, context window, benchmark scores and speed, all on one OpenAI-compatible API.

Gemini 3.8 Flash Googlegoogle/gemini-3.8-flash

GLM-5.3-Flash Z.aiz-ai/glm-5.3-flash

Creator

Google

Z.ai

Released

Sep 2, 2026

Aug 26, 2026

Context window

1.05M

1.31M

Max output

66K

131K

Input / 1MLowest provider price

$0.75

$0.07$0.07–$0.15 across 5

Output / 1MLowest provider price

$3.75

$0.25$0.25–$0.50 across 5

Providers

IntelligenceArtificial Analysis index

40.9

41.8

CodingArtificial Analysis index

76.3

71.5

Accepts

Text, Image, Audio, Video, Files

Text, Image, Video

Produces

Text

Tool calling

Yes

Structured output

Yes

Reasoning

Yes

Gemini 3.8 Flash vs GLM-5.3-Flash: summary

Gemini 3.8 Flash and GLM-5.3-Flash are both available through FastRouter's OpenAI-compatible API, so switching between them is a change of model id, not a new integration.

Gemini 3.8 Flash, from Google, has a 1,048,576-token context window, costs from $0.75/1M input and $3.75/1M output tokens across 2 providers and scores 40.9 on the Artificial Analysis Intelligence Index.

GLM-5.3-Flash, from Z.ai, has a 1,310,720-token context window, costs from $0.07/1M input and $0.25/1M output tokens across 5 providers and scores 41.8 on the Artificial Analysis Intelligence Index.

GLM-5.3-Flash is the cheapest on input, 11× cheaper than the next model, GLM-5.3-Flash has the largest context window, GLM-5.3-Flash scores highest for intelligence and Gemini 3.8 Flash leads on coding.

Switch with one line

client = OpenAI(base_url="https://api.fastrouter.ai/api/v1", api_key="<FASTROUTER_API_KEY>") client.chat.completions.create(model="google/gemini-3.8-flash", messages=[...]) # or client.chat.completions.create(model="z-ai/glm-5.3-flash", messages=[...])

Full API docs

Frequently asked questions

More comparisons

Benchmark scores sourced from ArtificialAnalysis