Grok 4.20 vs Qwen3.5 Plus 2026-04-20
Qwen3.5 Plus 2026-04-20 leads Grok 4.20 on coding, 39.5 to 33.3 on the Vibe Coding Index, and Qwen3.5 Plus 2026-04-20 costs 1.4x less per output token ($1.80 vs $2.50 per million). Updated October 22, 2026; 19 benchmarks have a result for both.
Grok 4.20 or Qwen3.5 Plus 2026-04-20: which to pick
Pick Qwen3.5 Plus 2026-04-20 for coding: it scores 39.5 on the Vibe Coding Index against 33.3 for Grok 4.20.
Pick Grok 4.20 for a lower cost per solved task ($0.72 against $1.35) and a larger context window (2M against 1M tokens).
- Shared results
- 19
- Grok 4.20 only
- 36
- Qwen3.5 Plus 2026-04-20 only
- 6
- Like-for-like categories
- 7 of 9
Only benchmarks that tested both models count toward a pick; a result only one model has is shown but not compared.
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
Qwen3.5 Plus 2026-04-20
Qwen3.5 Plus 2026-04-20 scores 39.5 against 33.3.
2 benchmarks behind each score
Intelligence
AA Intelligence Index
No call
Only Grok 4.20 has a AA Intelligence Index result, 25.7.
Directional only
Reasoning
GPQA Diamond
Grok 4.20
Grok 4.20 leads, 88.6% against 87.4%.
Same board, both measured
Math
AIME
Grok 4.20
Grok 4.20 leads, 96.5% against 86.0%.
Same board, both measured
Knowledge
MMLU Pro
Qwen3.5 Plus 2026-04-20
Qwen3.5 Plus 2026-04-20 leads, 87.2% against 86.3%.
Same board, both measured
Web design
Design Arena: websites
No call
Only Grok 4.20 has a Design Arena: websites result, 1229.
Directional only
Long documents
Listed context window
Grok 4.20
Grok 4.20 takes 2M tokens against 1M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Qwen3.5 Plus 2026-04-20
Grok 4.20 $0.0025, Qwen3.5 Plus 2026-04-20 $0.0012 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
Grok 4.20
Grok 4.20 $0.72, Qwen3.5 Plus 2026-04-20 $1.35.
Published attempt cost and pass rate
At a glance
- Coding index
- Grok 4.20 33.3 from 2 benchmarks, Qwen3.5 Plus 2026-04-20 39.5 from 2 benchmarks.
- Widest category
- Reasoning, 31.0 points apart on average over 2 shared benchmarks.
- Widest single gap
- MMMU Pro (Vals AI): Grok 4.20 83.5% against Qwen3.5 Plus 2026-04-20 22.8%, 60.7 points apart on a 0 to 100 scale.
- Output price
- Grok 4.20 $2.50 against Qwen3.5 Plus 2026-04-20 $1.80 per million output tokens, 1.4x apart.
- Context window
- Grok 4.20 takes 2M tokens, Qwen3.5 Plus 2026-04-20 1M.
Benchmark by benchmark
First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.
| Category | Grok 4.20 | Bars | Qwen3.5 Plus 2026-04-20 | Ties |
|---|---|---|---|---|
| Coding | 1 | 2 | ||
| Intelligence | 1 | 0 | ||
| Agentic work | 1 | 0 | ||
| Reasoning | 2 | 0 | ||
| Math | 1 | 0 | ||
| Knowledge | 0 | 6 | ||
| General | 4 | 1 | ||
| All shared boards | 10 | 9 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index12
| Benchmark | Grok 4.20 | Qwen3.5 Plus 2026-04-20 | Leader |
|---|---|---|---|
| LiveCodeBench (Vals AI) | 84.3% | 85.3% | Qwen3.5 Plus 2026-04-20 |
| SWE-bench Verified (Vals AI) | 72.2% | 71.2% | Grok 4.20 |
| Vibe Code Bench (Vals AI) | 4.1% | 15.7% | Qwen3.5 Plus 2026-04-20 |
| Code migration (Vals AI) | 0.3% | Not measured | Only Grok 4.20 measured |
| Terminal-Bench 2.1 (Vals AI) | 44.2% | Not measured | Only Grok 4.20 measured |
| Terminal-Bench Hard (Artificial Analysis run) | 37.9% | Not measured | Only Grok 4.20 measured |
| Terminal-Bench | 57.3% | Not measured | Only Grok 4.20 measured |
| WeirdML | 52.3% | Not measured | Only Grok 4.20 measured |
| ALE-Bench | Not measured | 608.9 | Only Qwen3.5 Plus 2026-04-20 measured |
| Neither model has a result on the other 34 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Grok 4.20 | Qwen3.5 Plus 2026-04-20 | Leader |
|---|---|---|---|
| AA Intelligence Index | 25.7 | Not measured | Only Grok 4.20 measured |
| Epoch Capabilities Index | 152.1 | 146.2 | Grok 4.20 |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Grok 4.20 | Qwen3.5 Plus 2026-04-20 | Leader |
|---|---|---|---|
| Design Arena: agents building web apps | 1144 | Not measured | Only Grok 4.20 measured |
| Design Arena: agents building full-stack apps | 1054 | Not measured | Only Grok 4.20 measured |
| Design Arena: agents building mobile apps | 1090 | Not measured | Only Grok 4.20 measured |
| Design Arena: agents building Android apps | 1045 | Not measured | Only Grok 4.20 measured |
| Design Arena: agents building Godot games | 1089 | Not measured | Only Grok 4.20 measured |
| Design Arena: HTML slides | 1180 | Not measured | Only Grok 4.20 measured |
| Finance Agent (Vals AI) | 28.5% | Not measured | Only Grok 4.20 measured |
| Tax Agent Bench (Vals AI) | 7.0% | Not measured | Only Grok 4.20 measured |
| Legal Research Bench (Vals AI) | 13.9% | Not measured | Only Grok 4.20 measured |
| Excel Modeling Benchmark (Vals AI) | 11.7% | Not measured | Only Grok 4.20 measured |
| τ²-Bench Telecom | 93.0% | Not measured | Only Grok 4.20 measured |
| Vending-Bench 2 | $4,663 | $1 | Grok 4.20 |
| Neither model has a result on the other 30 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Grok 4.20 | Qwen3.5 Plus 2026-04-20 | Leader |
|---|---|---|---|
| GPQA Diamond | 88.6% | 87.4% | Grok 4.20 |
| MMMU Pro (Vals AI) | 83.5% | 22.8% | Grok 4.20 |
| GPQA Diamond (Artificial Analysis run) | 91.1% | Not measured | Only Grok 4.20 measured |
| Humanity's Last Exam (Artificial Analysis run) | 34.5% | Not measured | Only Grok 4.20 measured |
| GPQA Diamond (Epoch AI run) | Not measured | 84.8% | Only Qwen3.5 Plus 2026-04-20 measured |
| ARC-AGI | 89.5% | Not measured | Only Grok 4.20 measured |
| ARC-AGI-2 | 65.1% | Not measured | Only Grok 4.20 measured |
| Chess puzzles | Not measured | 8.0% | Only Qwen3.5 Plus 2026-04-20 measured |
| Mystery game puzzles | Not measured | 17.0% | Only Qwen3.5 Plus 2026-04-20 measured |
| Kagi LLM Benchmark | 75.0% | Not measured | Only Grok 4.20 measured |
| Neither model has a result on the other 13 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Grok 4.20 | Qwen3.5 Plus 2026-04-20 | Leader |
|---|---|---|---|
| AIME | 96.5% | 86.0% | Grok 4.20 |
| OTIS Mock AIME | Not measured | 86.7% | Only Qwen3.5 Plus 2026-04-20 measured |
| Neither model has a result on the other 12 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index06
| Benchmark | Grok 4.20 | Qwen3.5 Plus 2026-04-20 | Leader |
|---|---|---|---|
| MMLU Pro | 86.3% | 87.2% | Qwen3.5 Plus 2026-04-20 |
| LegalBench (Vals AI) | 77.7% | 85.1% | Qwen3.5 Plus 2026-04-20 |
| CaseLaw (Vals AI) | 54.4% | 59.7% | Qwen3.5 Plus 2026-04-20 |
| CorpFin (Vals AI) | 63.7% | 65.3% | Qwen3.5 Plus 2026-04-20 |
| TaxEval (Vals AI) | 74.1% | Not measured | Only Grok 4.20 measured |
| MortgageTax (Vals AI) | 45.4% | 60.8% | Qwen3.5 Plus 2026-04-20 |
| MedQA (Vals AI) | 94.5% | 95.2% | Qwen3.5 Plus 2026-04-20 |
| MedCode (Vals AI) | 32.2% | Not measured | Only Grok 4.20 measured |
| SimpleQA Verified | Not measured | 25.4% | Only Qwen3.5 Plus 2026-04-20 measured |
| Neither model has a result on the other 11 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index8 boards, none shared
| Benchmark | Grok 4.20 | Qwen3.5 Plus 2026-04-20 | Leader |
|---|---|---|---|
| Design Arena: websites | 1229 | Not measured | Only Grok 4.20 measured |
| Design Arena: UI components | 1197 | Not measured | Only Grok 4.20 measured |
| Design Arena: game dev | 1193 | Not measured | Only Grok 4.20 measured |
| Design Arena: data viz | 1217 | Not measured | Only Grok 4.20 measured |
| Design Arena: 3D | 1193 | Not measured | Only Grok 4.20 measured |
| Design Arena: all code categories | 1221 | Not measured | Only Grok 4.20 measured |
| Design Arena: SVG | 1165 | Not measured | Only Grok 4.20 measured |
| Design Arena: ASCII art | 1175 | Not measured | Only Grok 4.20 measured |
| Neither model has a result on the other 1 board here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index41
| Benchmark | Grok 4.20 | Qwen3.5 Plus 2026-04-20 | Leader |
|---|---|---|---|
| SAGE (Vals AI) | 38.2% | 30.4% | Grok 4.20 |
| MedScribe (Vals AI) | 63.4% | Not measured | Only Grok 4.20 measured |
| Vals Multimodal Index | 39.1% | Not measured | Only Grok 4.20 measured |
| IFBench | 81.2% | Not measured | Only Grok 4.20 measured |
| Long context reasoning (AA-LCR) | 69.0% | Not measured | Only Grok 4.20 measured |
| DTBench | 90.1% | 80.5% | Grok 4.20 |
| LMCA | 38.7% | 36.4% | Grok 4.20 |
| CL-bench | 22.2% | 19.8% | Grok 4.20 |
| CL-bench Life | 11.9% | 12.4% | Qwen3.5 Plus 2026-04-20 |
| Neither model has a result on the other 39 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Grok 4.20 | Qwen3.5 Plus 2026-04-20 | Leader |
|---|---|---|---|
| Neither model has a result on 5 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
Qwen3.5 Plus 2026-04-20 costs less
Repository review
50K input + 3K output tokens
Qwen3.5 Plus 2026-04-20 costs less
Agent loop
200K input + 10K output tokens
Qwen3.5 Plus 2026-04-20 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 | SpaceXAI Grok 4.20 | Qwen3.5 Plus 2026-04-20 |
|---|---|---|
| Maker | xAI | Qwen |
| Weights | No public weights listed | No public weights listed |
| Released | March 31, 2026 | April 27, 2026 |
| Context window | 2M | 1M |
| Input $/Mtok | $1.25 | $0.30 |
| Output $/Mtok | $2.50 | $1.80 |
| Coding index | 33.3 | 39.5 |
| Independent measurements behind it | 2 | 2 |
| Cost per solved task | $0.72 | $1.35 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Grok 4.20 better than Qwen3.5 Plus 2026-04-20 for coding?
Pick Qwen3.5 Plus 2026-04-20 for coding: it scores 39.5 on the Vibe Coding Index against 33.3 for Grok 4.20. Pick Grok 4.20 for a lower cost per solved task ($0.72 against $1.35) and a larger context window (2M against 1M tokens).
Which is cheaper, Grok 4.20 or Qwen3.5 Plus 2026-04-20?
Grok 4.20 costs $1.25 per million input tokens and $2.50 per million output tokens; Qwen3.5 Plus 2026-04-20 costs $0.30 and $1.80. Per solved SWE-bench Verified task, Grok 4.20 costs $0.72 and Qwen3.5 Plus 2026-04-20 $1.35.
Which has the bigger context window, Grok 4.20 or Qwen3.5 Plus 2026-04-20?
Grok 4.20, with 2M tokens against 1M.
How many benchmarks is the Grok 4.20 vs Qwen3.5 Plus 2026-04-20 comparison based on?
19 benchmarks have a result for both models as of October 22, 2026. Grok 4.20's coding index rests on 2 independent benchmarks and Qwen3.5 Plus 2026-04-20's on 2. Where only one model has a result, the page says so instead of naming a winner.