MModelspectraIndependent AI Model Intelligence
Head-to-head · Updated 2026-09-08
Model Comparison · Head to Head

GLM-5.2 vs GPT-5.6 Terra

GLM-5.2 wins on Overall, Multimodal; GPT-5.6 Terra wins on Coding. Every numeric field is compared below, with a worked monthly-cost example and a pick rule for each use case.

VendorZhipu AI / OpenAI
Data fields15+ dimensions
Updated2026-09-08
Read~9 min
01

Verdict at a glance

Bottom line: Choose GLM-5.2 when lower refusal matter most; choose GPT-5.6 Terra when lower latency is the priority.

Choose GLM-5.2 if you…

  • Strong open-source ecosystem
  • Good Chinese
  • Mature enterprise services
  • Best for: Chinese, Open source, Coding

Choose GPT-5.6 Terra if you…

  • OpenAI quality
  • Halved price
  • Rich ecosystem
  • Best for: Value, General tasks, OpenAI ecosystem
02

Head-to-head aggregate scores

Scores are 0–100, aggregated from public benchmark information and independently weighted across three leaderboards. Rank is out of 22 tracked models.

GLM-5.2 Higher overall
Zhipu AI · #10 overall
Overall73
Coding66
Multimodal79
VS
GPT-5.6 Terra
OpenAI · #21 overall
Overall62
Coding70
Multimodal69

Aggregated from public sources and independently weighted; methodology on the Terms page. Scores within 3 points are treated as statistically tied.

03

Specs & pricing — every field side by side

List API prices in USD per 1M tokens. The highlighted cell is the stronger value/capability on that row.

DimensionGLM-5.2GPT-5.6 TerraVerdict
VendorZhipu AI (CN)OpenAI (US)Different vendors
Released2026.062026.07GPT-5.6 Terra is newer
Overall (rank)73 · #1062 · #21GLM-5.2 +11
Coding66 · #1570 · #12GPT-5.6 Terra +4
Multimodal79 · #1269 · #19GLM-5.2 +10
Context window128K1.05MGPT-5.6 Terra larger
Max output64K128KGLM-5.2 longer
Effective-context8888Tie
Input $/1M$1.4$2.5GLM-5.2 cheaper
Output $/1M$4.4$15GLM-5.2 cheaper
Cache discountnone50% offGPT-5.6 Terra deeper
Speed~50 tok/s~60 tok/sGPT-5.6 Terra faster
TTFT0.6s0.5sGPT-5.6 Terra snappier
Function calling8090GPT-5.6 Terra ahead
Refusal rate~8%~13%GLM-5.2 less restrictive
English7088GPT-5.6 Terra
Chinese9072GLM-5.2
Modalitiestext, imagetext, imageSame
Open weightsYesNoGLM-5.2 is open
Fine-tuningYesNo
Free tierChatGLM free; free quota on the open platformNo free API
SOC2 / no-trainno / yesyes / yes
Private deploymentYesNoGLM-5.2

Fields drawn from vendor public documentation and the Modelspectra 22-model dataset; speed varies with network, concurrency and prompt length. Verify current pricing before purchase.

04

Dimension-by-dimension analysis

Reasoning & overall intelligence

GLM-5.2 leads the overall aggregate by 11 points (73 vs 62). That is a meaningful, not marginal, edge on hard, multi-step reasoning, while GPT-5.6 Terra remains a strong generalist that is not out of its depth on routine work.

Agentic coding

This is a modest gap: GPT-5.6 Terra scores 70 against 66. On multi-file edits, SWE-style tickets and long-horizon agent loops GPT-5.6 Terra needs fewer correction turns; GLM-5.2 is still competent for scripts and assisted completion but trails as task complexity rises.

Multimodal

GLM-5.2 leads multimodal 79 vs 69. Neither emits native video, so the comparison is about parsing images and documents, not generation.

Speed & latency

GPT-5.6 Terra is faster in interactive use: ~60 tok/s with 0.5s TTFT versus ~50 tok/s with 0.6s TTFT (about 1.2× the throughput). For conversational UIs where perceived responsiveness drives retention, that edge is a real product factor even when raw reasoning is lower.

Context: window vs usable recall

Nominal windows are 128K for GLM-5.2 and 1.05M for GPT-5.6 Terra. Crucially, the larger nominal window does not win on usable recall: GPT-5.6 Terra advertises 1.05M but GLM-5.2 scores higher on effective-context (88 vs 88), i.e. it actually retains more of what it was given.

Price & total cost

GLM-5.2 is the cheaper API at $1.4/$4.4 versus GPT-5.6 Terra at $2.5/$15 per 1M input/output tokens — list input is about 1.8× lower. Cache discounts (GPT-5.6 Terra 50%) shift the effective bill, worked out below.

Chinese vs English

English: GLM-5.2 70 vs GPT-5.6 Terra 88. Chinese: 90 vs 72. For Chinese-language production, GLM-5.2 is the stronger pick. Note that non-Chinese models generally require overseas network access for their APIs.

Tool use & ecosystem

Function-calling score: GLM-5.2 80 vs GPT-5.6 Terra 90, so GPT-5.6 Terra has the edge on structured tool use. Fine-tuning is available from GLM-5.2. Factor in existing SDK/plugin familiarity — switching cost often outweighs a few-point tool-use gap.

05

Cost worked example — same workload, real token math

Assume a production workload of 100M input + 30M output tokens per month, with 90% of input tokens served from cache. Figures use public list prices.

Scenario · per monthGLM-5.2GPT-5.6 TerraGap
List priceno cache applied$272100M in × $1.4  +  30M out × $4.4$700100M in × $2.5  +  30M out × $152.57×gap
With caching90% of inputs cache-hit$272no published cache discount$58890M cached in × $1.25  +  10M in × $2.5  +  30M out × $152.16×gap

Illustrative model; your input/output mix and cache-hit ratio change the result. Prices are list rates before any enterprise agreement.

06

Decision tree

IF the workload is agentic or multi-file coding and a wrong first pass is expensive  →  choose GPT-5.6 Terra (coding 70 vs 66).
IF you serve real-time users and latency is a product KPI  →  choose GPT-5.6 Terra (~60 tok/s, 0.5s TTFT).
IF you are cost-driven at scale on routine, high-volume workloads  →  choose GLM-5.2 ($$1.4/$$4.4 per 1M in/out).
IF the product is Chinese-first  →  choose GLM-5.2 (Chinese 90 vs 72).
07

Frequently asked questions

Does GPT-5.6 Terra's higher refusal rate matter in production?
GPT-5.6 Terra refuses about 13% of prompts versus 8% for GLM-5.2. In unattended pipelines that means more retries, fallbacks and manual review, raising effective cost and latency even when the token price is lower.
How do costs compare at 100M tokens/month with caching?
At 100M input + 30M output with 90% of inputs cache-hit, GLM-5.2 is about $272/month and GPT-5.6 Terra about $588/month after cache discounts ($272 and $700 at list).
Does the bigger context window actually matter?
Nominal windows are GLM-5.2 (128K) and GPT-5.6 Terra (1.05M), but usable recall follows the effective-context score (88 vs 88). Prefer the higher effective-context model for long-document work where nothing can be missed.
How do they differ for Chinese-language and data-residency use?
GLM-5.2 is the Chinese model (Chinese score 90, domestic cloud, possible private deployment) while GPT-5.6 Terra is the global model (Chinese 72, overseas API). Pick by language quality, access path and where data must reside.
Can I self-host either model?
GLM-5.2 ships open weights and can be self-hosted (GPU permitting) for data control; GPT-5.6 Terra is a closed managed API with no self-hosting. Choose open weights when residency or cost-at-scale dominates, managed API for convenience.
Which one supports fine-tuning?
GLM-5.2 supports fine-tuning; GPT-5.6 Terra does not at this tier. If you plan to adapt the model to a narrow domain, that is a concrete differentiator.