Which is cheaper, Kimi K3.1 Pro and GLM-5.3?

GLM-5.3 has the lowest input price. Per 1M input tokens: Kimi K3.1 Pro from $2.00 and GLM-5.3 from $0.56.

Can I switch between Kimi K3.1 Pro and GLM-5.3 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 (moonshotai/kimi-k3.1-pro, z-ai/glm-5.3).

Kimi K3.1 Pro vs GLM-5.3

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

Estimate monthly cost for these models

Kimi K3.1 Pro MoonshotAImoonshotai/kimi-k3.1-pro

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

Creator

MoonshotAI

Z.ai

Released

Oct 23, 2026

Aug 18, 2026

Context window

1.05M

Max output

1.05M

131K

Input / 1MLowest provider price

$2.00

$0.56$0.56–$1.40 across 5

Output / 1MLowest provider price

$10.00

$2.48$2.48–$4.40 across 5

Providers

IntelligenceArtificial Analysis index

46.0

31.7

Accepts

Text, Image

Text

Produces

Text

Tool calling

Yes

Structured output

Yes

Reasoning

Yes

Kimi K3.1 Pro vs GLM-5.3: summary

Kimi K3.1 Pro and GLM-5.3 are both available through FastRouter's OpenAI-compatible API, so switching between them is a change of model id, not a new integration.

Kimi K3.1 Pro, from MoonshotAI, has a 1,048,576-token context window, costs $2.00/1M input and $10.00/1M output tokens and scores 46.0 on the Artificial Analysis Intelligence Index.

GLM-5.3, from Z.ai, has a 1,048,576-token context window, costs from $0.56/1M input and $2.48/1M output tokens across 5 providers and scores 31.7 on the Artificial Analysis Intelligence Index.

GLM-5.3 is the cheapest on input, 3.6× cheaper than the next model and Kimi K3.1 Pro scores highest for intelligence.

Switch with one line

client = OpenAI(base_url="https://api.fastrouter.ai/api/v1", api_key="<FASTROUTER_API_KEY>") client.chat.completions.create(model="moonshotai/kimi-k3.1-pro", messages=[...]) # or client.chat.completions.create(model="z-ai/glm-5.3", messages=[...])

Full API docs

Frequently asked questions

More comparisons

Benchmark scores sourced from ArtificialAnalysis