Claude Sonnet 4.6 vs GLM-5.1

Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.

Claude Sonnet 4.6

Anthropic · Apr 2026

Anthropic's mid-tier workhorse: near-Opus capability at $3/$15, and the leader on the Finance Agent benchmark.

GLM-5.1

Z.ai (Zhipu) · Apr 2026

The April 2026 GLM refresh — the first open-weights model to take #1 on SWE-bench Pro, edging out Claude Opus 4.6.

The verdict

These two models don't yet share verified results on the benchmarks we track, so judge them on specs, pricing and intended use. GLM-5.1 is about 2.8x cheaper per blended million tokens (3:1 input:output mix). Claude Sonnet 4.6 also takes 1M of context versus 200K for GLM-5.1. And GLM-5.1 is open-weights (MIT), so it can be self-hosted — a structural advantage if data control or vendor independence matters.

Specs & pricing

Claude Sonnet 4.6GLM-5.1
modhub Index
Input price / 1M$3$1.4
Output price / 1M$15$4.4
Context window1M200K
Max output64K128K
Open weightsnoyes (MIT)
Reasoning modelyesyes
Multimodal inputtext, imagetext
Knowledge cutoffJan 2026Feb 2026
ReleasedApr 2026Apr 2026
Example monthly cost*$52.50$20.60

* 10M input + 1.5M output tokens per month at list prices, no caching. Green = better value on that row.

Frequently asked questions

Which is better, Claude Sonnet 4.6 or GLM-5.1?
These two models don't yet share verified results on the benchmarks we track, so judge them on specs, pricing and intended use. GLM-5.1 is about 2.8x cheaper per blended million tokens (3:1 input:output mix). Claude Sonnet 4.6 also takes 1M of context versus 200K for GLM-5.1. And GLM-5.1 is open-weights (MIT), so it can be self-hosted — a structural advantage if data control or vendor independence matters.
Which is cheaper, Claude Sonnet 4.6 or GLM-5.1?
Claude Sonnet 4.6 costs $3/$15 per million input/output tokens, while GLM-5.1 costs $1.4/$4.4. For a typical workload of 10M input and 1.5M output tokens per month, that's $52.50 versus $20.60.
Which model is better for coding, Claude Sonnet 4.6 or GLM-5.1?
We don't yet track SWE-bench Verified results for both models; check their individual pages for coding-related scores.

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