comparison
Grok 4.20 vs GLM 4.6
Token pricing, context window and real monthly cost, side by side. GLM 4.6 is the cheaper of the two for a typical workload — about 1.8× less.
Positioned by published specs — size, context and modality — not measured performance; a smaller model can sometimes outperform a larger one on your task.
Grok 4.20 is one class larger (Flagship vs Mid). Lean to the cheaper GLM 4.6 unless your task is demanding enough to need the larger class.
| metric | Grok 4.20 | GLM 4.6 |
|---|---|---|
| Input / 1M | $1.25 | $0.50 |
| Output / 1M | $2.50 | $2.00 |
| Context | 2M | 205K |
| Technical class | Flagship | Mid |
| Cost @ typical workload | $625/mo | $350/mo |
| Modality | text + image | Text only |
| Price source | list | routed |
| Provider | xAI | Z.AI |
Snapshot . Cost uses a typical workload; tune it in the calculator. How we measure →
Which should you pick?
On a typical workload, GLM 4.6 costs $350/mo against Grok 4.20's $625/mo — roughly 1.8× cheaper. But the ranking depends on your output-to-input ratio: output is the pricier direction for both, so an output-heavy job (code generation, long answers) widens the gap while an input-heavy one (summarization, retrieval) narrows it. If you need to fit more in a single prompt, Grok 4.20 has the larger 2M-token window (~3,000 pages). Only Grok 4.20 accepts image input — decisive if your prompts include images. By technical class (size and context, not measured capability), Grok 4.20 is a Flagship and GLM 4.6 a Mid — so the lower price partly reflects a smaller class, not just a discount.
These are list and routed market prices, not measured outcomes. Two models at the same rate can still cost different amounts to finish the same task, because verbose or reasoning-heavy models emit more tokens. That gap is exactly what measured cost-per-task captures. The technical-class read above is likewise spec-based — size, context and modality, not measured performance — so a smaller model can still outperform a larger one on your specific task.
Frequently asked questions
Is Grok 4.20 or GLM 4.6 cheaper?
For a typical workload (1,500 input + 500 output tokens × 200,000 requests/month), GLM 4.6 costs $350/mo versus $625/mo for Grok 4.20 — about 1.8× less. Because output is priced higher than input, the winner can flip if your workload writes much more or less than this; check your own numbers in the calculator.
What's the main difference between Grok 4.20 and GLM 4.6?
On price, Grok 4.20 is $1.25/$2.50 per 1M (in/out) and GLM 4.6 is $0.50/$2.00. By technical class (size & context) it's Flagship (Grok 4.20) versus Mid (GLM 4.6). Grok 4.20 has the larger context window at 2M tokens. Only Grok 4.20 accepts image input.
Which handles longer prompts, Grok 4.20 or GLM 4.6?
Grok 4.20 — its 2M-token context window (~3,000 pages of text) is the larger of the two, by roughly 10×.
More comparisons
- GPT-5.4 mini vs Grok 4.20
- GPT-5.4 mini vs GLM 4.6
- Grok 4.20 vs GPT-5.4 nano
- GLM 4.6 vs GPT-5.4 nano
- Claude Haiku 4.5 vs Grok 4.20
- Claude Haiku 4.5 vs GLM 4.6
Related
- Grok 4.20 and GLM 4.6 — full specs and price history.
- API cost calculator — compare on your own workload.
- All comparisons — the full head-to-head index.