Kimi K3 vs GLM-5.3 vs DeepSeek V4.1: Price and Agent Routing

Kimi K3, GLM-5.3, and DeepSeek V4.1 Flash all offer roughly one-million-token context, but they occupy different cost and capability positions. GLM-5.3 now has pay-as-you-go pricing, and DeepSeek’s deepseek-flash endpoint now serves the cheaper, vision-capable V4.1 Flash.

Price Comparison

International API prices per million tokens:

Model	Input	Cached input	Output	Context	Maximum output
Kimi K3	$3.00	$0.30	$15.00	1M	Up to 1,048,576
GLM-5.3	$1.40	$0.26	$4.40	1M	128K
DeepSeek V4 Pro	$0.66-$1.32	$0.022-$0.044	$1.98-$3.96	1M	384K
DeepSeek V4.1 Flash	$0.15-$0.30	$0.003-$0.006	$0.60-$1.20	1M	384K

K3 costs more because it targets a broader frontier-agent role, not the budget routing tier. Whether the premium pays off depends on task completion, not parameter count.

Example Coding-Agent Bill

For 2M input and 500K output tokens, before cache hits:

Model	Cost per task
Kimi K3	$13.50
GLM-5.3	$5.00
DeepSeek V4 Pro	$2.31 off-peak / $4.62 peak
DeepSeek V4.1 Flash	$0.60 off-peak / $1.20 peak

K3 is 2.7 times the GLM-5.3 example cost and 11.25-22.5 times the DeepSeek V4.1 Flash cost, depending on the DeepSeek billing window. It needs a measurable advantage in multimodal understanding, long output, tool execution, or reduced retries to justify that gap.

Capability Differences

Kimi K3

K3 accepts text, image, and video, supports function calling and strict structured output, and can return exceptionally long completions. Its automatic prefix cache has no separate cache ID or TTL. The API currently always reasons at max.

Moonshot reports 2.8T total parameters with 16 of 896 experts active per token. Treat that architecture as context, not a quality guarantee.

GLM-5.3

GLM-5.3 is now the current priced Z.AI flagship for long-horizon coding and agent work. It keeps the $1.40/$4.40 input/output rates, 1M context, and 128K output limit. Lower-cost Flash and FlashX tiers are also available.

DeepSeek V4.1

V4.1 Flash is the cheaper scout. Its rate varies by time, with off-peak at half the weekday peak rate. V4 Pro costs more and should be used only where harder coding and agent steps measurably reduce retries.

V4.1 Flash now accepts images, while K3 also accepts video and permits much longer output. Choose based on the actual media and completion requirements rather than the old assumption that DeepSeek is text-only.

Recommended Multi-Model Routing

Agent step	Starting route
File search, classification, log summary	DeepSeek V4.1 Flash
Normal code patch or tool loop	DeepSeek V4.1 Flash or GLM-5.3
Very long engineering execution	GLM-5.3
Image/video-grounded task or output above 384K	Kimi K3
Difficult failure after cheaper routes	Kimi K3, then proprietary frontier fallback

Do not route solely by benchmark rank. Capture first-pass success, valid tool calls, wall-clock time, retries, cache hit rate, total output tokens, and human repair minutes.

Bottom Line

K3 is not the value winner on raw token price. It is the capability expansion: native image/video input, dynamic tools, and a completion ceiling that the other models do not match. GLM-5.3 is the balanced flagship route, while DeepSeek V4.1 Flash is the economic default for routine multimodal and text-heavy traffic.

Read the K3 API guide and the broader Chinese AI model pricing comparison, then test your workload in the AI Pricing Calculator.

Official sources checked September 25, 2026: Kimi global pricing, Z.AI pricing, GLM-5.3 docs, and DeepSeek pricing.