# Grok 4.5 vs Spark-X2.6-4B

> Side-by-side benchmark comparison for Grok 4.5 and Spark-X2.6-4B across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/grok-4-5-vs-spark-x2-6-4b
- Last updated: October 20, 2026

- Shared sourced benchmarks: 2
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Evidence is too thin for a benchmark verdict: Grok 4.5 and Spark-X2.6-4B share only 2 sourced benchmark rows.

## Summary

- Only 2 shared sourced benchmark rows are available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- Spark-X2.6-4B has the lower published output-token price.
- Spark-X2.6-4B has the larger published context window at 1M.

## Model Snapshot

| Property | Grok 4.5 | Spark-X2.6-4B |
|----------|----------|----------|
| Creator | xAI | SparkLLM |
| Type | Proprietary | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 500K | 1M |
| Independent public score (not head-to-head) | 63.29 | 40.14 |
| Benchmarks Covered | 19 | 20 |
| Pricing (input/output) | $2.00 / $6.00 | $0.00 / $0.00 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Grok 4.5 public-lane score: 58.8 (Supported · #32/131)
- Spark-X2.6-4B public-lane score: 33 (Estimated · #89/131)

| Benchmark | Grok 4.5 | Spark-X2.6-4B | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 3.0 | 15.7% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | 83.3% | Coming soon | Coming soon |
| deepSwe | 53% | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 67.8% | Coming soon | Coming soon |
| BFCL v4 | Coming soon | 71.8% | Coming soon |
| τ²-bench results | Coming soon | 86.9% | Coming soon |
| MCP Atlas | Coming soon | 62.4% | Coming soon |
| BrowseComp | Coming soon | 53.1% | Coming soon |
| HLE w/ tools | Coming soon | 36.9% | Coming soon |
| τ³-bench results | Coming soon | 34.7% | Coming soon |
| Claw-Eval | Coming soon | 69.9% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- Grok 4.5 public-lane score: 55.7 (Supported · #31/152)
- Spark-X2.6-4B public-lane score: 30.6 (Estimated · #95/152)

| Benchmark | Grok 4.5 | Spark-X2.6-4B | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Pro | 64.7% | 54.3% | Grok 4.5 |
| SWE Multilingual | 78% | 64.7% | Grok 4.5 |
| Terminal-Bench 2.1 | 83.3% | Coming soon | Coming soon |
| CursorBench 3.2 | 66.7% | Coming soon | Coming soon |
| VulcanBench v3 | 89.9% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 87.4% | Coming soon | Coming soon |
| SWE-bench (Vals) | 86.6% | Coming soon | Coming soon |
| PostTrainBench v1.1 | 23.4% | Coming soon | Coming soon |
| SWE-bench Verified | Coming soon | 62.8% | Coming soon |
| SciCode | Coming soon | 36.8% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- Grok 4.5 public-lane score: 54.1 (#27/27)
- Spark-X2.6-4B public-lane score: 48.8 (Unranked · 2 rankable rows)

| Benchmark | Grok 4.5 | Spark-X2.6-4B | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-2 | 52.6% | Coming soon | Coming soon |
| ARC-AGI-3 | 0.3% | Coming soon | Coming soon |
| ARC-AGI-1 | 85.67% | Coming soon | Coming soon |
| LongBench v2 | Coming soon | 53.3% | Coming soon |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- Grok 4.5 public-lane score: 82.9 (Unranked · 1 rankable row)
- Spark-X2.6-4B public-lane score: Coming soon

### Knowledge

- Winner: Insufficient shared evidence
- Grok 4.5 public-lane score: 67.4 (Supported · #28/187)
- Spark-X2.6-4B public-lane score: 43 (Estimated · #109/187)

| Benchmark | Grok 4.5 | Spark-X2.6-4B | Winner |
|-----------|-----------|-----------|--------|
| GPQA Diamond (Vals) | 92.9% | Coming soon | Coming soon |
| MMLU-Pro (Vals) | 89.2% | Coming soon | Coming soon |
| GPQA-D | Coming soon | 77.1% | Coming soon |
| HLE w/o tools | Coming soon | 17.9% | Coming soon |
| GPQA | Coming soon | 69.9% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- Grok 4.5 public-lane score: Coming soon
- Spark-X2.6-4B public-lane score: 78.2 (#62/149)

| Benchmark | Grok 4.5 | Spark-X2.6-4B | Winner |
|-----------|-----------|-----------|--------|
| IFEval | Coming soon | 93.6% | Coming soon |
| IFBench | Coming soon | 75.8% | Coming soon |

### Mathematics

- Winner: Insufficient shared evidence
- Grok 4.5 public-lane score: 62.9 (Unranked · 2 rankable rows)
- Spark-X2.6-4B public-lane score: 76.4 (Unranked · 3 rankable rows)

| Benchmark | Grok 4.5 | Spark-X2.6-4B | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath v2 (Tiers 1-3) | 57.193% | Coming soon | Coming soon |
| FrontierMath v2 (Tier 4) | 24.390% | Coming soon | Coming soon |
| AIME26 | Coming soon | 91.2% | Coming soon |
| HMMT Feb 2026 | Coming soon | 81.3% | Coming soon |
| IMOAnswerBench | Coming soon | 75.2% | Coming soon |

## FAQ

### Is there enough evidence to pick between Grok 4.5 and Spark-X2.6-4B?

Not yet. The models share only 2 sourced benchmark rows, so this mirror reports the available measurements and metadata without naming a broad winner.

### What can I compare safely on this page?

Published pricing, context windows, model type, and individual shared benchmark rows are directly comparable. Independent overall scores and non-overlapping benchmark coverage are labeled separately and should not be read as a controlled head-to-head result.

## Related Comparisons

- [Grok 4.5 vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-grok-4-5)
- [Spark-X2.6-4B vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-spark-x2-6-4b)
- [Grok 4.5 vs GPT-6.1 Sol](/compare/gpt-6-1-sol-vs-grok-4-5)
- [Spark-X2.6-4B vs GPT-6.1 Sol](/compare/gpt-6-1-sol-vs-spark-x2-6-4b)

## Explore More

- [Grok 4.5 profile](/models/grok-4-5)
- [Spark-X2.6-4B profile](/models/spark-x2-6-4b)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)