GPT-5.2 vs GLM 5
GPT-5.2 (OpenAI, released 2025-12-10) and GLM 5 (Z.ai, released 2026-02-11) both target agentic and coding workloads, but they land in different price and capability tiers. GPT-5.2 supports text, image, and file input with a 400,000-token context window; GLM 5 is text-only with 202,752 tokens of context but scores higher across Design Arena's agent benchmarks. The gap that matters most for most teams: GLM 5 is about a third the input cost of GPT-5.2. Both run on OpenKey with one API key and a flat 3% fee on provider list price.
Spec vs spec
| Spec | GPT-5.2 | GLM 5 |
|---|---|---|
| Context window | 400K | 203K |
| Max output | 128K | — |
| Input modalities | file, image, text | text |
| Output modalities | text | text |
| Released | Dec 10, 2025 | Feb 11, 2026 |
| Reasoning | optional | optional |
Pricing
Per 1M tokens. Provider price plus the flat 3% fee — the sum is what you pay.
openai/gpt-5.2
Input · 1M tokens
$1.75 + 3%$1.80
Output · 1M tokens
$14.00 + 3%$14.42
Cache read · 1M tokens
$0.175 + 3%$0.180
FEE — FLAT, EVERY MODEL3%
z-ai/glm-5
Input · 1M tokens
$0.600 + 3%$0.618
Output · 1M tokens
$1.92 + 3%$1.98
Cache read · 1M tokens
$0.120 + 3%$0.124
FEE — FLAT, EVERY MODEL3%
One workload, priced on both
10M input + 2M output tokens at each model's price, flat 3% fee included.
openai/gpt-5.2
$46.87
$45.50 provider + 3%
z-ai/glm-5Cheaper
$10.14
$9.84 provider + 3%
Benchmarks
Design Arena categories where both models have results. Higher Elo and lower rank win.
| GPT-5.2 | GLM 5 | |||
|---|---|---|---|---|
| Category | Elo | Rank | Elo | Rank |
| 3D | 1156 | #60 | 1307 | #15 |
| androidnative | 1074 | #22 | 1244 | #6 |
| ASCII art | 1199 | #22 | 1192 | #26 |
| Code | 1219 | #42 | 1295 | #16 |
| Data viz | 1245 | #31 | 1269 | #22 |
| Full-stack | 1110 | #21 | 1190 | #13 |
| Game dev | 1260 | #29 | 1299 | #15 |
| godotgamedev | 1183 | #13 | 1237 | #3 |
| Mobile apps | 1173 | #23 | 1222 | #10 |
| SVG | 1197 | #31 | 1225 | #19 |
| UI components | 1243 | #32 | 1287 | #21 |
| Websites | 1237 | #34 | 1290 | #18 |
Head-to-head preference voting. How we filter and rank
Pricing math
Provider list price for GPT-5.2 is $1.75/M input, $14.00/M output. On OpenKey that's $1.75 × 1.03 = $1.8025/M input and $14.00 × 1.03 = $14.42/M output. GLM 5 lists at $0.60/M input, $1.92/M output — on OpenKey that's $0.618/M input and $1.9776/M output. Run the numbers on a 10M-input / 2M-output workload: GPT-5.2 costs $45.50, GLM 5 costs $9.84. That's a 4.6x cost difference for the same shape of job. The input price ratio alone is 2.92x (GPT-5.2 costs 2.92x more per input token). If you're running high-volume agent loops, this delta compounds fast — a week of continuous agent calls on GPT-5.2 costs what GLM 5 costs in a month at the same volume.
Agentic coding performance
On Design Arena's agents arena, GLM 5 outranks GPT-5.2 in every shared category: android native (rank 6 vs 22), fullstack (rank 13 vs 21), Godot game dev (rank 3 vs 13), and mobile apps (rank 10 vs 23). GLM 5's Elo scores are higher across the board too — 1244 vs 1074 for android native, 1237 vs 1183 for Godot game dev. GPT-5.2 does hold win rates in the 44-49% range on these same categories, but GLM 5's win rates run higher (52.8-62%). For teams building autonomous coding agents or app-generation pipelines, GLM 5 is the stronger benchmark performer right now, not just the cheaper option.
Model-category benchmarks
In the models arena (single-shot generation tasks, not agent loops), GLM 5 leads on 3D (rank 15 vs 60), code categories (rank 16 vs 42), data viz (rank 22 vs 31), game dev (rank 15 vs 29), and UI components (rank 21 vs 32). GPT-5.2 only wins one category outright: ASCII art, where it ranks 22 against GLM 5's 26. Website generation is close — GPT-5.2 ranks 34, GLM 5 ranks 18, both mid-pack. Across 12 shared model-arena categories, GLM 5 places ahead of GPT-5.2 in 10 of them. If your evaluation criteria are Design Arena rank and cost, GLM 5 is the more defensible default for code-generation-heavy work.
Context and modality
GPT-5.2 supports text, image, and file input; GLM 5 is text-only. If your pipeline needs to parse screenshots, PDFs, or scanned documents, GPT-5.2 is the only option of the two. Context length also favors GPT-5.2: 400,000 tokens vs GLM 5's 202,752 — a ratio of 1.97x. GPT-5.2 also specifies a 128,000-token max completion limit; GLM 5 doesn't publish a max completion cap in this data. For long-document analysis, multi-file repo reviews, or workflows mixing text and images, GPT-5.2's wider input surface is the deciding factor regardless of price.
When to pick each
Pick GLM 5 for text-only coding agents, fullstack or mobile app generation, and any workload where cost per token matters at scale — it's cheaper and ranks higher on the agent benchmarks that matter for those tasks. Pick GPT-5.2 when you need image or file input, want the largest context window (400K tokens), or need a defined max completion ceiling (128,000 tokens) for long-form output. GPT-5.2 also exposes reasoning effort controls (xhigh, high, medium, low, none) for tuning latency vs quality, which GLM 5's supported parameters don't list explicitly.
Which model for which job
| Use case | Pick | Why |
|---|---|---|
| Autonomous coding agents (fullstack/mobile) | GLM 5 | Ranks 13 (fullstack) and 10 (mobile apps) vs GPT-5.2's 21 and 23 in the same Design Arena agent categories |
| High-volume API workloads | GLM 5 | 10M-in/2M-out workload costs $9.84 vs $45.50 on GPT-5.2 |
| Document or image analysis pipelines | GPT-5.2 | Only GPT-5.2 supports image and file input modalities; GLM 5 is text-only |
| Long-context repo or multi-doc review | GPT-5.2 | 400,000-token context vs GLM 5's 202,752, a 1.97x ratio |
| Game dev / Godot agent tasks | GLM 5 | Ranks 3rd in Design Arena's Godot game dev agent category vs GPT-5.2's 13th |
| Tunable reasoning depth per request | GPT-5.2 | Supports five reasoning effort levels (xhigh to none); GLM 5's parameter list doesn't expose this control |
Questions
- Is GLM 5 cheaper than GPT-5.2?
- Yes. GLM 5 costs $0.618/M input and $1.9776/M output on OpenKey (provider price $0.60/$1.92 plus the 3% fee). GPT-5.2 costs $1.8025/M input and $14.42/M output. On a 10M-input/2M-output workload, that's $9.84 for GLM 5 versus $45.50 for GPT-5.2.
- Which model has a bigger context window?
- GPT-5.2, at 400,000 tokens versus GLM 5's 202,752 — a ratio of 1.97x. If you're feeding in large codebases or long documents, GPT-5.2's window gives more headroom before you need to chunk input.
- Does GLM 5 support image input?
- No. GLM 5's input modality is text-only. GPT-5.2 supports text, image, and file input, so any workflow needing screenshots or scanned PDFs has to use GPT-5.2 or another multimodal model.
- Which model ranks higher for coding agents?
- GLM 5, in every shared Design Arena agents category: android native (rank 6 vs 22), fullstack (rank 13 vs 21), Godot game dev (rank 3 vs 13), and mobile apps (rank 10 vs 23), all against GPT-5.2.