Gemini 4 Hydrogen vs Grok 4.20
Gemini 4 Hydrogen leads Grok 4.20 on coding, 77.9 to 33.3 on the Vibe Coding Index, and Grok 4.20 costs 3.0x less per output token ($2.50 vs $7.50 per million). Updated November 14, 2026; 7 benchmarks have a result for both.
Gemini 4 Hydrogen or Grok 4.20: which to pick
Pick Gemini 4 Hydrogen for coding: it scores 77.9 on the Vibe Coding Index against 33.3 for Grok 4.20.
Pick Grok 4.20 for output tokens 3.0x cheaper ($2.50 vs $7.50 per million) and a larger context window (2M against 1.05M tokens).
- Shared results
- 7
- Gemini 4 Hydrogen only
- 43
- Grok 4.20 only
- 47
- Like-for-like categories
- 3 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
Gemini 4 Hydrogen
Gemini 4 Hydrogen scores 77.9 against 33.3.
4 and 2 benchmarks behind the scores
Reasoning
GPQA Diamond
No call
Only Grok 4.20 has a GPQA Diamond result, 88.6%.
Directional only
Math
AIME
No call
Only Grok 4.20 has a AIME result, 96.5%.
Directional only
Knowledge
MMLU Pro
No call
Only Grok 4.20 has a MMLU Pro result, 86.3%.
Directional only
Web design
Design Arena: websites
Gemini 4 Hydrogen
Gemini 4 Hydrogen leads, 1320 against 1221.
Same board, both measured
General
Vals Index
No call
Only Gemini 4 Hydrogen has a Vals Index result, 68.5%.
Directional only
Long documents
Listed context window
Grok 4.20
Grok 4.20 takes 2M tokens against 1.05M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Grok 4.20
Gemini 4 Hydrogen $0.0053, Grok 4.20 $0.0025 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Grok 4.20 has the number, $0.72.
Directional only
At a glance
- Coding index
- Gemini 4 Hydrogen 77.9 from 4 benchmarks, Grok 4.20 33.3 from 2 benchmarks.
- Widest category
- Coding, 83.7 points apart on average over 1 shared benchmark.
- Widest single gap
- Vibe Code Bench (Vals AI): Gemini 4 Hydrogen 87.8% against Grok 4.20 4.1%, 83.7 points apart on a 0 to 100 scale.
- Output price
- Gemini 4 Hydrogen $7.50 against Grok 4.20 $2.50 per million output tokens, 3.0x apart.
- Context window
- Gemini 4 Hydrogen takes 1.05M tokens, Grok 4.20 2M.
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 | Gemini 4 Hydrogen | Bars | Grok 4.20 | Ties |
|---|---|---|---|---|
| Coding | 1 | 0 | ||
| Agentic work | 2 | 0 | ||
| Web design | 4 | 0 | ||
| All shared boards | 7 | 0 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index10
| Benchmark | Gemini 4 Hydrogen | Grok 4.20 | Leader |
|---|---|---|---|
| LiveBench coding | 78.5% | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena WebDev | 1704 | Not measured | Only Gemini 4 Hydrogen measured |
| LiveCodeBench (Vals AI) | Not measured | 84.3% | Only Grok 4.20 measured |
| SWE-bench Verified (Vals AI) | Not measured | 72.2% | Only Grok 4.20 measured |
| Terminal-Bench 4 (Vals AI) | 54.0% | Not measured | Only Gemini 4 Hydrogen measured |
| Vibe Code Bench (Vals AI) | 87.8% | 4.1% | Gemini 4 Hydrogen |
| Code migration (Vals AI) | Not measured | 0.3% | Only Grok 4.20 measured |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 44.2% | Only Grok 4.20 measured |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 37.9% | Only Grok 4.20 measured |
| Terminal-Bench 4.0 (Artificial Analysis run) | 54.0% | Not measured | Only Gemini 4 Hydrogen measured |
| FrontierCode 2.0 | 39.0% | Not measured | Only Gemini 4 Hydrogen measured |
| Terminal-Bench | Not measured | 57.3% | Only Grok 4.20 measured |
| WeirdML | Not measured | 52.3% | Only Grok 4.20 measured |
| LMArena Text: coding | 1516 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: software and IT | 1513 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena WebDev: React | 1724 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena WebDev: HTML | 1743 | Not measured | Only Gemini 4 Hydrogen measured |
| Terminal-Bench 2.0 | Not measured | 57.3% | Only Grok 4.20 measured |
| CursorBench 4.0 | 57.8% | Not measured | Only Gemini 4 Hydrogen measured |
| Neither model has a result on the other 33 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | Gemini 4 Hydrogen | Grok 4.20 | Leader |
|---|---|---|---|
| Epoch Capabilities Index | Not measured | 152.3 | Only Grok 4.20 measured |
| Neither model has a result on the other 1 board here | |||
Agentic workLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Gemini 4 Hydrogen | Grok 4.20 | Leader |
|---|---|---|---|
| Design Arena: agents building web apps | Not measured | 1123 | Only Grok 4.20 measured |
| Design Arena: agents building full-stack apps | Not measured | 1028 | Only Grok 4.20 measured |
| Design Arena: agents building mobile apps | Not measured | 1082 | Only Grok 4.20 measured |
| Design Arena: agents building Android apps | Not measured | 1037 | Only Grok 4.20 measured |
| Design Arena: agents building Godot games | Not measured | 1089 | Only Grok 4.20 measured |
| Design Arena: HTML slides | Not measured | 1180 | Only Grok 4.20 measured |
| LiveBench research | 86.8% | Not measured | Only Gemini 4 Hydrogen measured |
| LiveBench browser | 77.1% | Not measured | Only Gemini 4 Hydrogen measured |
| LiveBench long agentic | 61.8% | Not measured | Only Gemini 4 Hydrogen measured |
| Finance Agent (Vals AI) | Not measured | 28.5% | Only Grok 4.20 measured |
| Tax Agent Bench (Vals AI) | 52.3% | 7.0% | Gemini 4 Hydrogen |
| Legal Research Bench (Vals AI) | 53.8% | 13.9% | Gemini 4 Hydrogen |
| Harvey's Legal Agent Benchmark (Vals AI) | 11.3% | Not measured | Only Gemini 4 Hydrogen measured |
| Excel Modeling Benchmark (Vals AI) | Not measured | 11.7% | Only Grok 4.20 measured |
| τ²-Bench Telecom | Not measured | 93.0% | Only Grok 4.20 measured |
| Vending-Bench 2 | Not measured | $4,663 | Only Grok 4.20 measured |
| Neither model has a result on the other 28 boards here | |||
ReasoningDirectional onlyPublic boards, shown as published, kept out of the index13 boards, none shared
| Benchmark | Gemini 4 Hydrogen | Grok 4.20 | Leader |
|---|---|---|---|
| GPQA Diamond | Not measured | 88.6% | Only Grok 4.20 measured |
| LiveBench reasoning | 88.6% | Not measured | Only Gemini 4 Hydrogen measured |
| MMMU Pro (Vals AI) | Not measured | 83.5% | Only Grok 4.20 measured |
| GPQA Diamond (Artificial Analysis run) | Not measured | 91.1% | Only Grok 4.20 measured |
| Humanity's Last Exam (Artificial Analysis run) | Not measured | 34.5% | Only Grok 4.20 measured |
| HLE-Diamond (Artificial Analysis run) | 58.8% | Not measured | Only Gemini 4 Hydrogen measured |
| CritPt v2, hard subset (Artificial Analysis run) | 66.0% | Not measured | Only Gemini 4 Hydrogen measured |
| ARC-AGI | Not measured | 89.5% | Only Grok 4.20 measured |
| ARC-AGI-2 | Not measured | 65.1% | Only Grok 4.20 measured |
| LMArena Text: hard prompts | 1520 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: expert | 1558 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: hard prompts in English | 1514 | Not measured | Only Gemini 4 Hydrogen measured |
| Kagi LLM Benchmark | Not measured | 75.0% | Only Grok 4.20 measured |
| Neither model has a result on the other 13 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index3 boards, none shared
| Benchmark | Gemini 4 Hydrogen | Grok 4.20 | Leader |
|---|---|---|---|
| AIME | Not measured | 96.5% | Only Grok 4.20 measured |
| LMArena Text: math | 1507 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: mathematical work | 1534 | Not measured | Only Gemini 4 Hydrogen measured |
| Neither model has a result on the other 11 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index13 boards, none shared
| Benchmark | Gemini 4 Hydrogen | Grok 4.20 | Leader |
|---|---|---|---|
| MMLU Pro | Not measured | 86.3% | Only Grok 4.20 measured |
| LegalBench (Vals AI) | Not measured | 77.7% | Only Grok 4.20 measured |
| CaseLaw (Vals AI) | Not measured | 54.4% | Only Grok 4.20 measured |
| CorpFin (Vals AI) | Not measured | 63.7% | Only Grok 4.20 measured |
| TaxEval (Vals AI) | Not measured | 74.1% | Only Grok 4.20 measured |
| MortgageTax (Vals AI) | Not measured | 45.4% | Only Grok 4.20 measured |
| MedQA (Vals AI) | Not measured | 94.5% | Only Grok 4.20 measured |
| MedCode (Vals AI) | Not measured | 32.2% | Only Grok 4.20 measured |
| AA-Omniscience | 46.3 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: science | 1519 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: medicine and healthcare | 1488 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: legal and government | 1532 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: business and finance | 1486 | Not measured | Only Gemini 4 Hydrogen measured |
| Neither model has a result on the other 8 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index40
| Benchmark | Gemini 4 Hydrogen | Grok 4.20 | Leader |
|---|---|---|---|
| Design Arena: websites | 1320 | 1221 | Gemini 4 Hydrogen |
| Design Arena: UI components | Not measured | 1191 | Only Grok 4.20 measured |
| Design Arena: game dev | 1369 | 1182 | Gemini 4 Hydrogen |
| Design Arena: data viz | Not measured | 1214 | Only Grok 4.20 measured |
| Design Arena: 3D | 1415 | 1172 | Gemini 4 Hydrogen |
| Design Arena: all code categories | 1333 | 1210 | Gemini 4 Hydrogen |
| Design Arena: SVG | Not measured | 1153 | Only Grok 4.20 measured |
| Design Arena: ASCII art | Not measured | 1170 | Only Grok 4.20 measured |
| LiveBench design | 77.3% | Not measured | Only Gemini 4 Hydrogen measured |
GeneralDirectional onlyPublic boards, shown as published, kept out of the index23 boards, none shared
| Benchmark | Gemini 4 Hydrogen | Grok 4.20 | Leader |
|---|---|---|---|
| Vals Index | 68.5% | Not measured | Only Gemini 4 Hydrogen measured |
| LiveBench data analysis | 83.2% | Not measured | Only Gemini 4 Hydrogen measured |
| MedScribe (Vals AI) | Not measured | 63.4% | Only Grok 4.20 measured |
| Vals Multimodal Index | Not measured | 39.1% | Only Grok 4.20 measured |
| IFBench | Not measured | 81.2% | Only Grok 4.20 measured |
| Long context reasoning (AA-LCR) | Not measured | 69.0% | Only Grok 4.20 measured |
| DTBench | Not measured | 90.1% | Only Grok 4.20 measured |
| LMCA | Not measured | 38.7% | Only Grok 4.20 measured |
| CL-bench | Not measured | 22.2% | Only Grok 4.20 measured |
| CL-bench Life | Not measured | 11.9% | Only Grok 4.20 measured |
| LMArena Text | 1502 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: instruction following | 1519 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: creative writing | 1509 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: English | 1499 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: non-English | 1495 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: Chinese | 1631 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: French | 1512 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: Spanish | 1494 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: Russian | 1492 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: multi-turn | 1485 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: longer queries | 1524 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: writing and language | 1500 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: entertainment and media | 1503 | Not measured | Only Gemini 4 Hydrogen measured |
| Neither model has a result on the other 26 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Gemini 4 Hydrogen | Grok 4.20 | 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
Grok 4.20 costs less
Repository review
50K input + 3K output tokens
Grok 4.20 costs less
Agent loop
200K input + 10K output tokens
Grok 4.20 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 | Google Gemini 4 Hydrogen | SpaceXAI Grok 4.20 |
|---|---|---|
| Maker | xAI | |
| Weights | No public weights listed | No public weights listed |
| Released | November 12, 2026 | March 31, 2026 |
| Context window | 1.05M | 2M |
| Input $/Mtok | $1.50 | $1.25 |
| Output $/Mtok | $7.50 | $2.50 |
| Coding index | 77.9 | 33.3 |
| Independent measurements behind it | 4 | 2 |
| Cost per solved task | Not computable | $0.72 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Gemini 4 Hydrogen better than Grok 4.20 for coding?
Pick Gemini 4 Hydrogen for coding: it scores 77.9 on the Vibe Coding Index against 33.3 for Grok 4.20. Pick Grok 4.20 for output tokens 3.0x cheaper ($2.50 vs $7.50 per million) and a larger context window (2M against 1.05M tokens).
Which is cheaper, Gemini 4 Hydrogen or Grok 4.20?
Gemini 4 Hydrogen costs $1.50 per million input tokens and $7.50 per million output tokens; Grok 4.20 costs $1.25 and $2.50. Cost per solved task is known for Grok 4.20 only.
Which has the bigger context window, Gemini 4 Hydrogen or Grok 4.20?
Grok 4.20, with 2M tokens against 1.05M.
How many benchmarks is the Gemini 4 Hydrogen vs Grok 4.20 comparison based on?
7 benchmarks have a result for both models as of November 14, 2026. Gemini 4 Hydrogen's coding index rests on 4 independent benchmarks and Grok 4.20's on 2. Where only one model has a result, the page says so instead of naming a winner.