GLM 5.3 FlashX vs o4 Mini High
Updated October 21, 2026. No benchmark has tested both models yet. Coding is ranked on the Vibe Coding Index; every other board is shown as published.
- Coding
- No data
- Overall
- No data
- Output $/M
- $1.25
- Coding
- No data
- Overall
- No data
- Output $/M
- $4.40
Decision reading
Neither model has a coding score yet, so the two cannot be ranked on coding.
GLM 5.3 FlashX has the edge where output tokens cost 3.5x less, and where the context window is larger, 1.05M against 200K tokens.
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
Long documents
Listed context window
GLM 5.3 FlashX
GLM 5.3 FlashX takes 1.05M tokens against 200K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
GLM 5.3 FlashX
GLM 5.3 FlashX $0.0010, o4 Mini High $0.0033 per turn.
List prices
At a glance
- Coding index
- GLM 5.3 FlashX not benchmarked, o4 Mini High 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 FlashX $1.25 against o4 Mini High $4.40 per million output tokens, 3.5x apart.
- Context window
- GLM 5.3 FlashX takes 1.05M tokens, o4 Mini High 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 Index1 board measured
| Benchmark | GLM 5.3 FlashX | o4 Mini High | Leader |
|---|---|---|---|
| ALE-Bench | Not measured | 826.2 | Only o4 Mini High measured |
| Neither model has a result on the other 37 boards here | |||
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index1 board measured
| Benchmark | GLM 5.3 FlashX | o4 Mini High | Leader |
|---|---|---|---|
| GDPval | Not measured | 25.3% | Only o4 Mini High measured |
| Neither model has a result on the other 38 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 FlashX costs less
Repository review
50K input + 3K output tokens
GLM 5.3 FlashX costs less
Agent loop
200K input + 10K output tokens
GLM 5.3 FlashX 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 FlashX | OpenAI o4 Mini High |
|---|---|---|
| Maker | Z.ai | OpenAI |
| Weights | No public weights listed | No public weights listed |
| Released | September 18, 2026 | April 16, 2025 |
| Context window | 1.05M | 200K |
| Input $/Mtok | $0.37 | $1.10 |
| Output $/Mtok | $1.25 | $4.40 |
| 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 FlashX better than o4 Mini High for coding?
Neither model has a coding score yet, so the two cannot be ranked on coding. GLM 5.3 FlashX has the edge where output tokens cost 3.5x less, and where the context window is larger, 1.05M against 200K tokens.
Which is cheaper, GLM 5.3 FlashX or o4 Mini High?
GLM 5.3 FlashX costs $0.37 per million input tokens and $1.25 per million output tokens; o4 Mini High costs $1.10 and $4.40. Cost per solved task is known for neither of them.
Which has the bigger context window, GLM 5.3 FlashX or o4 Mini High?
GLM 5.3 FlashX, with 1.05M tokens against 200K.
Has any benchmark tested both GLM 5.3 FlashX and o4 Mini High?
No benchmark has tested both yet. GLM 5.3 FlashX has none yet; o4 Mini High on ALE-Bench and GDPval. Compare them on price and context instead. Data as of October 21, 2026.