GPT-5.6 Sol vs GLM-5.2
OpenAI's GPT-5.6 Sol and Z.ai's GLM-5.2 both target production language workloads, but they price and behave differently. Here is the side-by-side.
Pricing checked against provider documentation on . How we verify
The short answer
GLM-5.2 is the cheaper option — roughly 3.7x less on a blended workload, and it suits mit-licensed coding agents. GPT-5.6 Sol justifies its premium when you need frontier coding and long-horizon agents.
OpenAI • GPT-5.6
$4.00 / $20.00
/ 1M tokens (input / output)
OpenAI's flagship tier and the current state of the art on agentic coding benchmarks. Reasoning effort is tunable from none through max, and an `ultra` setting coordinates parallel subagents across workstreams. Sol reaches near-Fable-5 intelligence while spending markedly fewer output tokens, which is why its cost per finished task lands well below its sticker price.
Z.ai • GLM-5
$1.40 / $4.40
/ 1M tokens (input / output)
A 744B-parameter MoE with 40B active, MIT-licensed, and tuned for long-horizon coding work. It sits between DeepSeek and Kimi on price and is the usual challenger when a cheaper model keeps looping or missing repository conventions — enough capability to finish the task without flagship pricing.
Input price
GLM-5.2 is 65% cheaper than GPT-5.6 Sol on input tokens.
Output price
GLM-5.2 is 78% cheaper than GPT-5.6 Sol on output tokens — usually the side that dominates the bill.
Monthly cost at three workload sizes
Standard (non-batch, non-cached) rates. Reasoning models will exceed these figures because thinking tokens bill as output.
| Workload | GPT-5.6 Sol | GLM-5.2 | Difference |
|---|---|---|---|
| Light — 1M in / 200K out | $8 | $2 | $6 |
| Moderate — 10M in / 2M out | $80 | $23 | $57 |
| Heavy — 100M in / 20M out | $800 | $228 | $572 |
Specification comparison
| Attribute | GPT-5.6 Sol | GLM-5.2 |
|---|---|---|
| Input (/ 1M tokens) | $4.00 | $1.40 |
| Output (/ 1M tokens) | $20.00 | $4.40 |
| Cached input | $0.40 | $0.26 |
| Context window | 1,048,576 tokens | 1,000,000 tokens |
| Max output | 128,000 tokens | 131,072 tokens |
| Native reasoning | Yes | Yes |
| Knowledge cutoff | 2026-02 | 2026-02 |
| Relative latency | high | medium |
| Open weights | No | MIT |
| API model ID | gpt-5.6-sol | glm-5.2 |
| Status | stable | stable |
GPT-5.6 Sol: Promotional pricing (down from $5/$30) held at least through 2026-11-21. Prompts above 272K input tokens bill at higher rates; 'fast' processing is 2x.
GLM-5.2: Independently measured by Artificial Analysis; the vendor's own pricing page was unreachable at time of checking. Treat as approximate and confirm in the console.
Choose GPT-5.6 Sol if…
- Long-running autonomous coding agents
- Large-scale refactors and migrations
- Agentic browsing and computer use
- Scientific and financial analysis
Choose GLM-5.2 if…
- Coding agents on large repositories
- Long-horizon refactors
- Self-hosted agent stacks
- Structured output pipelines
Frequently asked
Is GPT-5.6 Sol or GLM-5.2 cheaper?
GLM-5.2 is cheaper. On a blended 3:1 input-to-output workload it costs about 3.7x less than GPT-5.6 Sol.
Which has the larger context window, GPT-5.6 Sol or GLM-5.2?
GPT-5.6 Sol has the larger window at 1.05M tokens versus 1M.
Should I use GPT-5.6 Sol or GLM-5.2?
Pick GPT-5.6 Sol for frontier coding and long-horizon agents. Pick GLM-5.2 for mit-licensed coding agents. If cost dominates the decision, GLM-5.2 wins; if you need the capability ceiling, benchmark both on your own evals before committing.