Question 1

What is GLM 5.1?

Accepted Answer

GLM 5.1 is a model from Z.ai, released on Apr 7, 2026. GLM-5.1 delivers a major leap in coding capability, with particularly significant gains in handling long-horizon tasks. Unlike previous models built around minute-level interactions, GLM-5.1 can work independently and continuously on a single task for more than 8 hours, autonomously planning, executing, and improving itself throughout the process, ultimately delivering complete, engineering-grade results.

Question 2

How much does GLM 5.1 cost?

Accepted Answer

On the Respan gateway, input starts at $0.82 per 1M tokens on EmpirioLabs, and output starts at $3.30 per 1M tokens on EmpirioLabs, after gateway discounts. Averaged across 9 providers, it costs $1.31 per 1M input tokens and $4.22 per 1M output tokens.

Question 3

Which providers serve GLM 5.1 on Respan?

Accepted Answer

9 providers serve GLM 5.1: EmpirioLabs, Novita, Featherless, IO.net, FriendliAI, Nebius, and 3 more. TogetherAI requires your own provider API key (BYOK).

Question 4

What is GLM 5.1's context window?

Accepted Answer

GLM 5.1 accepts up to 205K tokens of context on its largest provider route.

Question 5

How do I use GLM 5.1 with the Respan gateway?

Accepted Answer

Point any OpenAI-compatible SDK at https://api.respan.ai/api/ with your Respan API key and set the model to "zai/glm-5.1". To set it up with a coding agent, copy the agent setup prompt at the top of this page.

Question 6

How fast is GLM 5.1?

Accepted Answer

Over the last 30 days of requests through the Respan gateway, the fastest provider was FriendliAI at 65 tokens per second, and the lowest response latency was 1.1 seconds on IO.net. Speed varies with request size and provider.

Question 7

Where does GLM 5.1 rank on the Respan Index?

Accepted Answer

GLM 5.1 scores 34.4 out of 100 on the Respan Index v1.1, ranking #55 of 138 models. By category: Coding 13.2, Agents 53.9, Reasoning 25.1, Knowledge & language 34.0, and Human preference 52.9. The Respan Index combines independent and lab-reported benchmark results into one score, using benchmark data collected by llmmetric.com.

Question 8

How does GLM 5.1 score on benchmarks?

Accepted Answer

GLM 5.1 has 15 published benchmark scores, including SWE-bench Verified 74.2%, APEX-Agents 40.9%, and GPQA Diamond 89.9%. Each score links to where it was published; the data is collected by llmmetric.com.

Provider	Context	Input	Output
EmpirioLabs`empiriolabs/glm-5-1`	202K	$0.82/M	$3.30/M
NovitaSave 10%`novita/zai-org/glm-5.1`	205K	$1.24/M	$3.96/M
Featherless`featherless_ai/zai-org/GLM-5.1`	203K	$1.30/M	$4.30/M
IO.net`ionet/zai-org/GLM-5.1`	203K	$1.38/M	$4.38/M
FriendliAI`friendliai/zai-org/GLM-5.1`	203K	$1.40/M	$4.40/M
Nebius`nebius/zai-org/GLM-5.1`	203K	$1.40/M	$4.40/M
OpenRouter`openrouter/z-ai/glm-5.1`	205K	$1.40/M	$4.40/M
TogetherAIBYOK only`together_ai/zai-org/GLM-5.1`	203K	$1.40/M	$4.40/M
Z.ai`zai/glm-5.1`	200K	$1.40/M	$4.40/M

GLM 5.1

Providers

Certified where it counts.

Pricing

Cost by volume

Throughput and latency

Output speed

Response latency

Benchmarks

Respan Indexv1.1

Coding2

Agents

Apps

GLM 5.1 FAQ

Works with your entire stack

Built for AI agents.
Break less.
Ship more.

Reasoning3

Math4

Knowledge2

Arena2