Model comparison
GLM-5.3 vs Step 3.5 Flash
GLM-5.3 is the stronger model overall, scoring 54.8 to 42.3 on the Noometry Index. Step 3.5 Flash costs 14× less per token, which makes it the better buy when GLM-5.3's lead doesn't matter for your workload.
Last verified . 18 shared benchmarks.
StepFunSummary
- They share 18 benchmarks with published results for both. GLM-5.3 scores higher in 8 categories and Step 3.5 Flash in 0 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where GLM-5.3 leads 46.1 to 22.2.
- The biggest single-benchmark swing is NYT Connections (extended): 74.2% for GLM-5.3 and 28.4% for Step 3.5 Flash.
- Step 3.5 Flash is cheaper at $0.10 / $0.30 per million input/output tokens, against $1.40 / $4.40 for GLM-5.3.
- GLM-5.3 accepts more context: 1M tokens versus 256K.
Side by side
| GLM-5.3 | Step 3.5 Flash | |
|---|---|---|
| Provider | Z.ai (Zhipu) | StepFun |
| Noometry Index | 54.8 | 42.3 |
| Released | 2026-08-14 | 2026-01-29 |
| Weights | Open | Open |
| Context window | 1M | 256K |
| Max output | 131K | 256K |
| Input $ / M tokens | $1.40 | $0.10 |
| Output $ / M tokens | $4.40 | $0.30 |
| Results tracked | 42 | 19 |
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Category by category
Coding GLM-5.3 leads
GLM-5.3: 59.5 (#14), Step 3.5 Flash: 42.4 (#105)
| Benchmark | GLM-5.3 | Step 3.5 Flash |
|---|---|---|
| LMArena Coding | 1496 | 1436 |
| DeepSWE | 69% | — |
| FrontierCode | 40.1% | — |
| CursorBench | 42.6% | — |
| LMArena WebDev | 1622 | — |
| FrontierSWE | 30.2% | — |
| SciCode | 59% | — |
| WeirdML | 75.4% | — |
| ALE-Bench | 1,317 | — |
Agentic & Tool Use Not comparable
GLM-5.3: 36.4 (#38), Step 3.5 Flash: —
| Benchmark | GLM-5.3 | Step 3.5 Flash |
|---|---|---|
| APEX-Agents | 56.6% | — |
| Vending-Bench 2 | 8,164 | — |
Reasoning GLM-5.3 leads
GLM-5.3: 46.1 (#46), Step 3.5 Flash: 22.2 (#202)
| Benchmark | GLM-5.3 | Step 3.5 Flash |
|---|---|---|
| NYT Connections (extended) | 74.2% | 28.4% |
| LMArena Hard Prompts | 1489 | 1411 |
| CritPt | 19.1% | — |
| Chess Puzzles | 21% | — |
| Mystery Game Puzzles | 33% | — |
| DTBench | 87.7% | — |
| LMCA | 55.5% | — |
| Bench to the Future 3 | 0.15 | — |
| Epoch Capabilities Index | 155.61 | — |
Math GLM-5.3 leads
GLM-5.3: 62.3 (#33), Step 3.5 Flash: 42.6 (#84)
| Benchmark | GLM-5.3 | Step 3.5 Flash |
|---|---|---|
| LMArena Math | 1489 | 1408 |
| FrontierMath (Tiers 1-3) | 68.8% | — |
| FrontierMath Tier 4 | 29.3% | — |
| MathArena Final-Answer Competitions | — | 66.8% |
| OTIS Mock AIME 2024-2025 | 91.1% | — |
| ProofBench | 49% | — |
Knowledge GLM-5.3 leads
GLM-5.3: 58.3 (#37), Step 3.5 Flash: 39.6 (#132)
| Benchmark | GLM-5.3 | Step 3.5 Flash |
|---|---|---|
| LMArena Expert | 1516 | 1421 |
| GPQA Diamond | 90.9% | — |
| SimpleQA Verified | 41% | — |
Multilingual GLM-5.3 leads
GLM-5.3: 55.7 (#28), Step 3.5 Flash: 50.5 (#119)
| Benchmark | GLM-5.3 | Step 3.5 Flash |
|---|---|---|
| LMArena Non-English | 1457 | 1385 |
| LMArena Chinese | 1528 | 1447 |
| LMArena French | 1499 | 1421 |
| LMArena German | 1499 | 1405 |
| LMArena Japanese | 1453 | 1354 |
| LMArena Korean | 1472 | 1352 |
| LMArena Russian | 1463 | 1385 |
| LMArena Spanish | 1460 | 1419 |
Instruction Following GLM-5.3 leads
GLM-5.3: 77.5 (#23), Step 3.5 Flash: 73.1 (#124)
| Benchmark | GLM-5.3 | Step 3.5 Flash |
|---|---|---|
| LMArena Instruction Following | 1477 | 1385 |
Long Context GLM-5.3 leads
GLM-5.3: 45.4 (#41), Step 3.5 Flash: 42.8 (#117)
| Benchmark | GLM-5.3 | Step 3.5 Flash |
|---|---|---|
| LMArena Longer Query | 1482 | 1402 |
Writing & Preference GLM-5.3 leads
GLM-5.3: 75.7 (#6), Step 3.5 Flash: 58.8 (#113)
| Benchmark | GLM-5.3 | Step 3.5 Flash |
|---|---|---|
| LMArena Text | 1471 | 1403 |
| LMArena Creative Writing | 1457 | 1357 |
| LMArena Multi-Turn | 1472 | 1405 |
| EQ-Bench Creative Writing | 2075 | — |
Frequently asked questions
Is GLM-5.3 better than Step 3.5 Flash?
GLM-5.3 is the stronger model overall, scoring 54.8 to 42.3 on the Noometry Index. Step 3.5 Flash costs 14× less per token, which makes it the better buy when GLM-5.3's lead doesn't matter for your workload.
Which is cheaper, GLM-5.3 or Step 3.5 Flash?
Step 3.5 Flash is cheaper. It lists at $0.10 per million input tokens and $0.30 per million output tokens; GLM-5.3 lists at $1.40 and $4.40.
Is GLM-5.3 or Step 3.5 Flash better for coding?
GLM-5.3 scores higher on coding benchmarks: 59.5 versus 42.4 in the Noometry coding category.
Which has the bigger context window?
GLM-5.3 does, with 1M tokens against 256K.
How many benchmarks do GLM-5.3 and Step 3.5 Flash share?
18 benchmarks have published results for both models. GLM-5.3 has 42 scored results on Noometry and Step 3.5 Flash has 19.