Which is cheaper, Kimi K3 and GLM-5.3-Flash?

GLM-5.3-Flash has the lowest input price. Per 1M input tokens: Kimi K3 from $2.70 and GLM-5.3-Flash from $0.07.

Which has the larger context window, Kimi K3 and GLM-5.3-Flash?

GLM-5.3-Flash has the largest context window: Kimi K3 1,048,576 tokens and GLM-5.3-Flash 1,310,720 tokens.

Which is better for coding, Kimi K3 and GLM-5.3-Flash?

Kimi K3 scores highest on the Artificial Analysis Coding Index: Kimi K3 76.2 and GLM-5.3-Flash 71.5.

Which is smarter, Kimi K3 and GLM-5.3-Flash?

Kimi K3 scores highest on the Artificial Analysis Intelligence Index: Kimi K3 43.6 and GLM-5.3-Flash 41.8.

Can I switch between Kimi K3 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 (moonshotai/kimi-k3, z-ai/glm-5.3-flash).

Kimi K3 vs GLM-5.3-Flash

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

Kimi K3 MoonshotAImoonshotai/kimi-k3

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

Creator

MoonshotAI

Z.ai

Released

Jul 16, 2026

Aug 26, 2026

Context window

1.05M

1.31M

Max output

1.05M

131K

Input / 1MLowest provider price

$2.70$2.70–$3.00 across 4

$0.07$0.07–$0.15 across 5

Output / 1MLowest provider price

$13.50$13.50–$15.00 across 4

$0.25$0.25–$0.50 across 5

Providers

IntelligenceArtificial Analysis index

43.6

41.8

CodingArtificial Analysis index

76.2

71.5

LatencyMedian time to first token

7.4s

—

ThroughputMedian tokens per second

<1 t/s

—

Accepts

Text, Image

Text, Image, Video

Produces

Text

Tool calling

Yes

Structured output

Yes

Reasoning

Yes

Kimi K3 vs GLM-5.3-Flash: summary

Kimi K3 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.

Kimi K3, from MoonshotAI, has a 1,048,576-token context window, costs from $2.70/1M input and $13.50/1M output tokens across 4 providers and scores 43.6 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, 39× cheaper than the next model, GLM-5.3-Flash has the largest context window, Kimi K3 scores highest for intelligence and Kimi K3 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="moonshotai/kimi-k3", 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