Long documents
Prompts that approach the documented context limit
Grok Code Fast 1
Grok Code Fast 1 has the larger documented context window.
Confidence: documented
Grok Code Fast 1 vs Qwen3.5 397B
Updated September 29, 2026. We do not rank this pair: at least one has no public score. Public scores include evidence status and uncertainty.
Both of these models will change. Get the price, version and retirement notices for the pair, each with its source. Follow model changes
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Decision reading
At least one model is not scored in the current public ranking lane, so the page does not name an overall quality winner. 1 results are shared. Category rows resting on Estimated evidence or different benchmark sets are marked directional and do not name a winner.
- Shared results
- 1
- Grok Code Fast 1 only
- 1
- Qwen3.5 397B only
- 37
- Like-for-like categories
- 0 / 8
Estimated: Grok Code Fast 1How the comparison works
Which one for your work
Recommendations appear only when a shared evidence basis or an explicit operating constraint supports the call. Secondary and unsupported use cases stay disclosed below the initial list.
Chat turn cost
1K fresh input + 500 output tokens
Grok Code Fast 1
Grok Code Fast 1 has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.
Confidence: listed-rates
Show secondary and unsupported calls
Repository review cost
50K fresh input + 3K output tokens
Grok Code Fast 1
Grok Code Fast 1 has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.
Confidence: listed-ratesCoding work
Code generation, repair, and software-engineering tasks
Not enough matched evidence
Qwen3.5 397B is not ranked on the public lane for coding, so no winner is named for coding.
Confidence: limitedAgentic work
Tool use, computer use, and multi-step task completion
Not enough matched evidence
Grok Code Fast 1 and Qwen3.5 397B are not ranked on the public lane for agentic, so no winner is named for agentic.
Confidence: limitedCache-heavy agent loop cost
200K cached + 20K fresh input + 10K output tokens
Not enough matched evidence
The page does not recommend a cost winner because at least one model cannot fit the stated workload in one request. Qwen3.5 397B does not fit this workload in one request. Grok Code Fast 1 has no published cached-input rate, so cached tokens use its listed input rate. Qwen3.5 397B has no published cached-input rate, so cached tokens use its listed input rate.
Confidence: rate-fallback
Which one for a specific job
Choose a job from the LLM Selector's task catalog to see the category row it rests on, under the same basis rules as the table below. A directional row stays directional; choosing a job never creates a winner.
The same task catalog as the LLM Selector. Each job names the evidence surface it rests on; nothing here adds a new score.
21.5Grok Code Fast 1—Qwen3.5 397B
Not comparable · BenchAlign v5.7
The coding row is not comparable on the public lane: at least one model is not measured or not ranked there.
Coding scores combine specific tasks and setups. Match the editor, harness, and effort to your workflow.
Same basis rules as the category table below
What is actually comparable
Shared results can support a head-to-head reading. Results present for only one model describe coverage, not superiority.
1 Grok Code Fast 1 only
1 Shared
37 Qwen3.5 397B only
1 category rests on Estimated evidence or different evidence sets. Those rows remain visible for coverage context but do not name a winner.
Shape of the matched evidence
Only shared public evidence is shown. Sparse evidence stays a ruled list rather than being closed into a radar shape.
Too few matched category axes support a radar. The ruled list below shows only shared benchmark results; positions use each benchmark’s normalized display scale when available.
SWE-bench VerifiedCoding
Normalized gap 5.4Grok Code Fast 1:70.8%Qwen3.5 397B:76.2%
Bars run 0–100 on each benchmark’s normalized display scale
Category results, on a stated basis
Each row shows the public-lane category score for both models: the BenchAlign v5.7 lane for agentic, coding, and knowledge, and the weighted public rows elsewhere, with the same rank each model page reports. A row is like-for-like only when both scores rest on Supported evidence or the same weighted set. Directional and not-comparable rows remain visible, but they never receive a winner.
Instruction following
Directional only- Grok Code Fast 1
- 46.8
- #87/124
- Qwen3.5 397B
- 0.0
- #124/124
- Basis
- Provisional lane · 0 vs 0 weighted rows
- Reading
- Directional only
Agentic
Not comparable- Grok Code Fast 1
- Not ranked
- Qwen3.5 397B
- Not ranked
- Basis
- BenchAlign v5.7 lane · 0 vs 13 public rows
- Reading
- Not comparable
Coding
Not comparable- Grok Code Fast 1
- 21.5
- Estimated · #119/143
- Qwen3.5 397B
- Not ranked
- Basis
- BenchAlign v5.7 lane · 2 vs 3 public rows
- Reading
- Not comparable
Reasoning
Not comparable- Grok Code Fast 1
- 58.7
- Unranked · 2 rankable rows
- Qwen3.5 397B
- 61.0
- Unranked · 2 rankable rows
- Basis
- Provisional lane · 0 vs 1 weighted rows
- Reading
- Not comparable
Multimodal
Not comparable- Grok Code Fast 1
- Not ranked
- Qwen3.5 397B
- 63.9
- #28/50
- Basis
- Provisional lane · 0 vs 2 weighted rows
- Reading
- Not comparable
Knowledge
Not comparable- Grok Code Fast 1
- 36.0
- Estimated · #112/169
- Qwen3.5 397B
- Not ranked
- Basis
- BenchAlign v5.7 lane · 0 vs 6 public rows
- Reading
- Not comparable
Multilingual
Not comparable- Grok Code Fast 1
- Not ranked
- Qwen3.5 397B
- 69.7
- #5/12
- Basis
- Provisional lane · 0 vs 1 weighted rows
- Reading
- Not comparable
Math
Not comparable- Grok Code Fast 1
- Not ranked
- Qwen3.5 397B
- 73.5
- Unranked · 5 rankable rows
- Basis
- Provisional lane · 0 vs 2 weighted rows
- Reading
- Not comparable
| Category | Grok Code Fast 1 | Qwen3.5 397B | Basis | Reading |
|---|---|---|---|---|
| Instruction following | 46.8#87/124 | 0.0#124/124 | Directional onlyProvisional lane · 0 vs 0 weighted rows | Directional only |
| Agentic | Not ranked | Not ranked | Not comparableBenchAlign v5.7 lane · 0 vs 13 public rows | Not comparable |
| Coding | 21.5Estimated · #119/143 | Not ranked | Not comparableBenchAlign v5.7 lane · 2 vs 3 public rows | Not comparable |
| Reasoning | 58.7Unranked · 2 rankable rows | 61.0Unranked · 2 rankable rows | Not comparableProvisional lane · 0 vs 1 weighted rows | Not comparable |
| Multimodal | Not ranked | 63.9#28/50 | Not comparableProvisional lane · 0 vs 2 weighted rows | Not comparable |
| Knowledge | 36.0Estimated · #112/169 | Not ranked | Not comparableBenchAlign v5.7 lane · 0 vs 6 public rows | Not comparable |
| Multilingual | Not ranked | 69.7#5/12 | Not comparableProvisional lane · 0 vs 1 weighted rows | Not comparable |
| Math | Not ranked | 73.5Unranked · 5 rankable rows | Not comparableProvisional lane · 0 vs 2 weighted rows | Not comparable |
Ranks count the models scored in each category’s lane, so the agentic, coding, and knowledge denominators (BenchAlign v5.7) differ from the provisional-lane categories. Unranked scores sit on the provisional lane’s scale but never name a winner. Like-for-like rows within 0.5 points read as a practical tie.
Bars run 0–100Methodology
What each workload costs
Three fixed token mixes turn per-token rates into comparable decisions. Each scenario states context fit and whether cached input had to fall back to the published list-input rate.
Chat turn
1K fresh input + 500 output tokens
- Grok Code Fast 1
- $0.00095
- Fits in one request
- Qwen3.5 397B
- $0.0024
- Fits in one request
Grok Code Fast 1 has the lower modeled cost
Costs use the listed standard API rates.
Repository review
50K fresh input + 3K output tokens
- Grok Code Fast 1
- $0.0145
- Fits in one request
- Qwen3.5 397B
- $0.0408
- Fits in one request
Grok Code Fast 1 has the lower modeled cost
Costs use the listed standard API rates.
Cache-heavy agent loop
200K cached + 20K fresh input + 10K output tokens
- Grok Code Fast 1
- $0.059
- Fits in one request
- Cached input priced at the published list-input rate
- Qwen3.5 397B
- $0.168
- Does not fit in one request
- Cached input priced at the published list-input rate
Qwen3.5 397B does not fit this workload in one request. Grok Code Fast 1 has no published cached-input rate, so cached tokens use its listed input rate. Qwen3.5 397B has no published cached-input rate, so cached tokens use its listed input rate.
Cached input falls back to the list input rate only where a cached rate is unpublished
Specification differences
Sourced differences are shown directly. Missing facts stay explicit instead of being inferred from a model name or family.
SpecificationGrok Code Fast 1Qwen3.5 397B
Context window
Maximum documented context; output-token limits may be lower.
Grok Code Fast 1
256K
Qwen3.5 397B
128K
API model ID
Grok Code Fast 1
Not sourced
Qwen3.5 397B
Not sourced
Cached-input rate
A missing cached-input rate falls back to the listed input rate only in the stated workload estimate.
Grok Code Fast 1
Not published
Qwen3.5 397B
Not published
Documented inputs
Grok Code Fast 1
Not sourced
Qwen3.5 397B
Not sourced
Documented outputs
Grok Code Fast 1
Not sourced
Qwen3.5 397B
Not sourced
Provider availability
Grok Code Fast 1
Not sourced
Qwen3.5 397B
Not sourced
Reasoning profile
Grok Code Fast 1
Non-Reasoning
Qwen3.5 397B
Non-Reasoning
Weight access
Grok Code Fast 1
Proprietary
Qwen3.5 397B
Open Weight
License
Grok Code Fast 1
Proprietary
Qwen3.5 397B
Open Weight
Release date
Grok Code Fast 1
2025-08-28
Qwen3.5 397B
2026-02-16
If you already use one of these models
- Deployment change
- The models list different providers, so authentication, endpoint behavior, limits, and feature support may change.
- Quality signal
- At least one model is not scored in the current public ranking lane, so the page does not name an overall quality winner.
- Workload cost
- Repository review: $0.0145 vs $0.0408. Cache-heavy agent loop: $0.059 vs $0.168.
- Context tradeoff
- Grok Code Fast 1 has the larger documented window (256K).
Run the same representative tasks against both endpoints before changing production traffic.
Questions
Which is better, Grok Code Fast 1 or Qwen3.5 397B?
At least one model is not scored in the current public ranking lane, so the page does not name an overall quality winner. The page therefore keeps the decision tied to the specific documented workload.
Which is better for coding, Grok Code Fast 1 or Qwen3.5 397B?
Qwen3.5 397B is not ranked on the public lane for coding, so no winner is named for coding.
Which is better for agentic tasks, Grok Code Fast 1 or Qwen3.5 397B?
Grok Code Fast 1 and Qwen3.5 397B are not ranked on the public lane for agentic tasks, so no winner is named for agentic tasks.
Which costs less, Grok Code Fast 1 or Qwen3.5 397B?
For the stated presets, chat costs $0.00095 on Grok Code Fast 1 and $0.0024 on Qwen3.5 397B; repository review costs $0.0145 and $0.0408; the cache-heavy agent loop costs $0.059 and $0.168. Qwen3.5 397B does not fit this workload in one request. Grok Code Fast 1 has no published cached-input rate, so cached tokens use its listed input rate. Qwen3.5 397B has no published cached-input rate, so cached tokens use its listed input rate.
Which has the larger context window, Grok Code Fast 1 or Qwen3.5 397B?
Grok Code Fast 1 has the larger documented context window: 256K, compared with 128K.
Benchmark evidence
The full public result ledger is available for audit without forcing a wide desktop table onto a phone.
Browse raw public benchmark evidence39 rows
Agentic
Terminal-Bench 2.0
Grok Code Fast 1—Qwen3.5 397B52.5%SourceNot directly comparable
BrowseComp
Grok Code Fast 1—Qwen3.5 397B62%SourceNot directly comparable
Claw-Eval
Grok Code Fast 1—Qwen3.5 397B56.8%SourceNot directly comparable
QwenClawBench
Grok Code Fast 1—Qwen3.5 397B51.8%SourceNot directly comparable
τ³-bench results
Grok Code Fast 1—Qwen3.5 397B68.4%SourceNot directly comparable
VITA-Bench
Grok Code Fast 1—Qwen3.5 397B43.7%SourceNot directly comparable
DeepPlanning
Grok Code Fast 1—Qwen3.5 397B37.6%SourceNot directly comparable
Toolathlon
Grok Code Fast 1—Qwen3.5 397B36.3%SourceNot directly comparable
MCP Atlas
Grok Code Fast 1—Qwen3.5 397B46.1%SourceNot directly comparable
MCP-Tasks
Grok Code Fast 1—Qwen3.5 397B74.2%SourceNot directly comparable
WideResearch
Grok Code Fast 1—Qwen3.5 397B74.0%SourceNot directly comparable
Gert Labs
Grok Code Fast 1—Qwen3.5 397B46.76%SourceNot directly comparable
ResearchClawBench
Grok Code Fast 1—Qwen3.5 397B14.2%SourceNot directly comparable
Coding
SWE-bench Verified
Grok Code Fast 170.8%SourceQwen3.5 397B76.2%SourceQwen3.5 397B leads this result
LiveCodeBench (Vals)
Grok Code Fast 162.0%SourceQwen3.5 397B—Not directly comparable
LiveCodeBench v6
Grok Code Fast 1—Qwen3.5 397B83.6%SourceNot directly comparable
SWE-bench Pro
Grok Code Fast 1—Qwen3.5 397B50.9%SourceNot directly comparable
Reasoning
Multimodal
MMMU-Pro
Grok Code Fast 1—Qwen3.5 397B79%SourceNot directly comparable
MathVision
Grok Code Fast 1—Qwen3.5 397B88.6%SourceNot directly comparable
CharXiv
Grok Code Fast 1—Qwen3.5 397B80.8%SourceNot directly comparable
VideoMMMU
Grok Code Fast 1—Qwen3.5 397B84.7%SourceNot directly comparable
ScreenSpot Pro
Grok Code Fast 1—Qwen3.5 397B65.6%SourceNot directly comparable
V*
Grok Code Fast 1—Qwen3.5 397B95.8%SourceNot directly comparable
Knowledge
GPQA
Grok Code Fast 1—Qwen3.5 397B88.4%SourceNot directly comparable
SuperGPQA
Grok Code Fast 1—Qwen3.5 397B70.4%SourceNot directly comparable
MMLU-Pro
Grok Code Fast 1—Qwen3.5 397B87.8%SourceNot directly comparable
MMLU-Redux
Grok Code Fast 1—Qwen3.5 397B94.9%SourceNot directly comparable
C-Eval
Grok Code Fast 1—Qwen3.5 397B93%SourceNot directly comparable
HLE
Grok Code Fast 1—Qwen3.5 397B28.7%SourceNot directly comparable
Multilingual
Instruction following
IFEval
Grok Code Fast 1—Qwen3.5 397B92.6%SourceNot directly comparable
Math
AIME26
Grok Code Fast 1—Qwen3.5 397B93.3%SourceNot directly comparable
HMMT Feb 2025
Grok Code Fast 1—Qwen3.5 397B94.8%SourceNot directly comparable
HMMT Nov 2025
Grok Code Fast 1—Qwen3.5 397B92.7%SourceNot directly comparable
HMMT Feb 2026
Grok Code Fast 1—Qwen3.5 397B87.9%SourceNot directly comparable
MMAnswerBench
Grok Code Fast 1—Qwen3.5 397B80.9%SourceNot directly comparable
39 public results · 1 shared
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Last updated September 29, 2026