GLM 5.3 Prime vs o3 Pro
GLM 5.3 Prime costs 9.1x less per output token than o3 Pro ($8.80 vs $80.00 per million). Updated October 22, 2026; no benchmark has tested both models yet.
- Coding
- No data
- Overall
- No data
- Output $/M
- $8.80
- Coding
- No data
- Overall
- No data
- Output $/M
- $80.00
GLM 5.3 Prime or o3 Pro: which to pick
Neither model has a coding score yet, so the two cannot be ranked on coding.
Pick GLM 5.3 Prime for output tokens 9.1x cheaper ($8.80 vs $80.00 per million) and a larger context window (1M against 200K tokens).
No benchmark has tested both yet. GLM 5.3 Prime has none yet; o3 Pro on Aider polyglot, WeirdML and AA Intelligence Index. Compare them on price and context instead.
Which one for your work
Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.
Coding
Vibe Coding Index, six public coding benchmarks
No call
Neither has a coding score yet.
One side not measured
Intelligence
AA Intelligence Index
No call
Only o3 Pro has a AA Intelligence Index result, 21.9.
Directional only
Long documents
Listed context window
GLM 5.3 Prime
GLM 5.3 Prime takes 1M tokens against 200K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
GLM 5.3 Prime
GLM 5.3 Prime $0.0072, o3 Pro $0.060 per turn.
List prices
At a glance
- Coding index
- GLM 5.3 Prime not benchmarked, o3 Pro not benchmarked.
- Widest category
- None yet: no category has been tested on both models.
- Widest single gap
- None yet: no benchmark has tested both models.
- Output price
- GLM 5.3 Prime $8.80 against o3 Pro $80.00 per million output tokens, 9.1x apart.
- Context window
- GLM 5.3 Prime takes 1M tokens, o3 Pro 200K.
Benchmark by benchmark
Every board either model has a result on, a category to a fold; bars are each result on a 0 to 100 scale. Only one model is measured on each, so no row names a leader.
CodingDirectional onlySix of these boards feed the Vibe Coding Index2 boards measured
| Benchmark | GLM 5.3 Prime | o3 Pro | Leader |
|---|---|---|---|
| Aider polyglot | Not measured | 84.9% | Only o3 Pro measured |
| WeirdML | Not measured | 58.2% | Only o3 Pro measured |
| Neither model has a result on the other 37 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index2 boards measured
| Benchmark | GLM 5.3 Prime | o3 Pro | Leader |
|---|---|---|---|
| AA Intelligence Index | Not measured | 21.9 | Only o3 Pro measured |
| Epoch Capabilities Index | Not measured | 147.3 | Only o3 Pro measured |
ReasoningDirectional onlyPublic boards, shown as published, kept out of the index4 boards measured
| Benchmark | GLM 5.3 Prime | o3 Pro | Leader |
|---|---|---|---|
| GPQA Diamond (Artificial Analysis run) | Not measured | 84.5% | Only o3 Pro measured |
| ARC-AGI | Not measured | 59.3% | Only o3 Pro measured |
| ARC-AGI-2 | Not measured | 4.9% | Only o3 Pro measured |
| Kagi LLM Benchmark | Not measured | 72.1% | Only o3 Pro measured |
| Neither model has a result on the other 18 boards here | |||
GeneralDirectional onlyPublic boards, shown as published, kept out of the index4 boards measured
| Benchmark | GLM 5.3 Prime | o3 Pro | Leader |
|---|---|---|---|
| DTBench | Not measured | 86.9% | Only o3 Pro measured |
| LMCA | Not measured | 38.5% | Only o3 Pro measured |
| Fiction.LiveBench | Not measured | 97.2% | Only o3 Pro measured |
| Creative writing (Lech Mazur) | Not measured | 84.4% | Only o3 Pro measured |
| Neither model has a result on the other 42 boards here | |||
What each workload costs
Three fixed token mixes at each model's listed price, so per-token rates become a bill.
Chat turn
1K input + 500 output tokens
GLM 5.3 Prime costs less
Repository review
50K input + 3K output tokens
GLM 5.3 Prime costs less
Agent loop
200K input + 10K output tokens
GLM 5.3 Prime costs less
Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.
Specification differences
The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.
| Specification | Z.ai GLM 5.3 Prime | OpenAI o3 Pro |
|---|---|---|
| Maker | Z.ai | OpenAI |
| Weights | No public weights listed | No public weights listed |
| Released | September 23, 2026 | June 10, 2025 |
| Context window | 1M | 200K |
| Input $/Mtok | $2.80 | $20.00 |
| Output $/Mtok | $8.80 | $80.00 |
| Coding index | Not benchmarked | Not benchmarked |
| Independent measurements behind it | 0 | 0 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GLM 5.3 Prime better than o3 Pro for coding?
Neither model has a coding score yet, so the two cannot be ranked on coding. Pick GLM 5.3 Prime for output tokens 9.1x cheaper ($8.80 vs $80.00 per million) and a larger context window (1M against 200K tokens).
Which is cheaper, GLM 5.3 Prime or o3 Pro?
GLM 5.3 Prime costs $2.80 per million input tokens and $8.80 per million output tokens; o3 Pro costs $20.00 and $80.00. Cost per solved task is known for neither of them.
Which has the bigger context window, GLM 5.3 Prime or o3 Pro?
GLM 5.3 Prime, with 1M tokens against 200K.
Has any benchmark tested both GLM 5.3 Prime and o3 Pro?
No benchmark has tested both yet. GLM 5.3 Prime has none yet; o3 Pro on Aider polyglot, WeirdML and AA Intelligence Index. Compare them on price and context instead. Data as of October 22, 2026.