Agentic
Not comparable- Solar Open 2
- Not ranked
- Step 5 Preview
- Not ranked
- Basis
- BenchAlign lane · 3 vs 11 public rows
- Reading
- Not comparable
Solar Open 2 vs Step 5 Preview
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.
3 results are shared. Category rows resting on Estimated evidence or different benchmark sets are marked directional and do not name a winner.
Updated September 21, 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
Share or export
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.
No workload recommendation clears the current evidence threshold.
Use the matched evidence, workload costs, and sourced specifications below instead of treating a point score as a universal answer.
Show secondary and unsupported calls
Coding work
Code generation, repair, and software-engineering tasks
Not enough matched evidence
Solar Open 2 and Step 5 Preview are not ranked on the public lane for coding, so no winner is named for coding.
Confidence: limited
Agentic work
Tool use, computer use, and multi-step task completion
Not enough matched evidence
Solar Open 2 and Step 5 Preview are not ranked on the public lane for agentic, so no winner is named for agentic.
Confidence: limited
Long documents
Prompts that approach the documented context limit
No clear pick
The documented context windows are equal.
Confidence: documented
Chat turn cost
1K fresh input + 500 output tokens
Not enough matched evidence
A complete comparable API-rate estimate is not available for both models.
Confidence: listed-rates
Cache-heavy agent loop cost
200K cached + 20K fresh input + 10K output tokens
Not enough matched evidence
A complete comparable API-rate estimate is not available for both models.
Confidence: listed-rates
Repository review cost
50K fresh input + 3K output tokens
Not enough matched evidence
A complete comparable API-rate estimate is not available for both models.
Confidence: listed-rates
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.
—Solar Open 2—Step 5 Preview
Not comparable · BenchAlign
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.
What is actually comparable
Shared results can support a head-to-head reading. Results present for only one model describe coverage, not superiority.
8 Solar Open 2 only
3 Shared
19 Step 5 Preview only
- Shared results
- 3
- Solar Open 2 only
- 8
- Step 5 Preview only
- 19
- Like-for-like categories
- 0 / 8
Category results, on a stated basis
Each row shows the public-lane category score for both models: the BenchAlign 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.
Coding
Not comparable- Solar Open 2
- Not ranked
- Step 5 Preview
- Not ranked
- Basis
- BenchAlign lane · 2 vs 6 public rows
- Reading
- Not comparable
Reasoning
Not comparable- Solar Open 2
- Not ranked
- Step 5 Preview
- 78.5
- Unranked · 2 rankable rows
- Basis
- Provisional lane · 0 vs 0 weighted rows
- Reading
- Not comparable
Multimodal
Not comparable- Solar Open 2
- Not ranked
- Step 5 Preview
- 61.2
- #28/49
- Basis
- Provisional lane · 0 vs 2 weighted rows
- Reading
- Not comparable
Knowledge
Not comparable- Solar Open 2
- Not ranked
- Step 5 Preview
- Not ranked
- Basis
- BenchAlign lane · 3 vs 2 public rows
- Reading
- Not comparable
Multilingual
Not comparable- Solar Open 2
- Not ranked
- Step 5 Preview
- Not ranked
- Basis
- Provisional lane · 0 vs 0 weighted rows
- Reading
- Not comparable
Instruction following
Not comparable- Solar Open 2
- Not ranked
- Step 5 Preview
- Not ranked
- Basis
- Provisional lane · 1 vs 0 weighted rows
- Reading
- Not comparable
Math
Not comparable- Solar Open 2
- Not ranked
- Step 5 Preview
- Not ranked
- Basis
- Provisional lane · 2 vs 0 weighted rows
- Reading
- Not comparable
| Category | Solar Open 2 | Step 5 Preview | Basis | Reading |
|---|---|---|---|---|
| Agentic | Not ranked | Not ranked | Not comparableBenchAlign lane · 3 vs 11 public rows | Not comparable |
| Coding | Not ranked | Not ranked | Not comparableBenchAlign lane · 2 vs 6 public rows | Not comparable |
| Reasoning | Not ranked | 78.5Unranked · 2 rankable rows | Not comparableProvisional lane · 0 vs 0 weighted rows | Not comparable |
| Multimodal | Not ranked | 61.2#28/49 | Not comparableProvisional lane · 0 vs 2 weighted rows | Not comparable |
| Knowledge | Not ranked | Not ranked | Not comparableBenchAlign lane · 3 vs 2 public rows | Not comparable |
| Multilingual | Not ranked | Not ranked | Not comparableProvisional lane · 0 vs 0 weighted rows | Not comparable |
| Instruction following | Not ranked | Not ranked | Not comparableProvisional lane · 1 vs 0 weighted rows | Not comparable |
| Math | Not ranked | Not ranked | Not comparableProvisional lane · 2 vs 0 weighted rows | Not comparable |
Ranks count the models scored in each category’s lane, so the agentic, coding, and knowledge denominators (BenchAlign) differ from the provisional-lane categories. Unranked scores sit on the lane’s scale but never name a winner. Like-for-like rows within 0.5 points read as a practical tie.
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.
A shared-evidence shape is not available.
BenchLM does not draw a radar or infer missing axes when the matched evidence is too sparse.
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
- Solar Open 2
- Self-hosted; infrastructure cost varies
- Fits in one request
- Step 5 Preview
- $0.00235
- Fits in one request
Solar Open 2 has no comparable published API token rate.
Repository review
50K fresh input + 3K output tokens
- Solar Open 2
- Self-hosted; infrastructure cost varies
- Fits in one request
- Step 5 Preview
- $0.0581
- Fits in one request
Solar Open 2 has no comparable published API token rate.
Cache-heavy agent loop
200K cached + 20K fresh input + 10K output tokens
- Solar Open 2
- Self-hosted; infrastructure cost varies
- Fits in one request
- Cached-input rate unavailable
- Step 5 Preview
- $0.057
- Fits in one request
Solar Open 2 has no comparable published API token rate.
Specification differences
Sourced differences are shown directly. Missing facts stay explicit instead of being inferred from a model name or family.
SpecificationSolar Open 2Step 5 Preview
Context window
Maximum documented context; output-token limits may be lower.
Solar Open 2
Step 5 Preview
API model ID
Solar Open 2
upstage/Solar-Open2-250B
Upstage Solar Open 2 model cardStep 5 Preview
step-5-preview
StepFun Step 5 Preview model documentationCached-input rate
A missing cached-input rate falls back to the listed input rate only in the stated workload estimate.
Solar Open 2
No comparable hosted API rate
Upstage Solar Open 2 model cardStep 5 Preview
$0.05 per 1M cached input tokens
StepFun pricing and rate limitsDocumented inputs
Solar Open 2
Not sourced
Step 5 Preview
text, image, video
StepFun Step 5 Preview model documentationDocumented outputs
Solar Open 2
Not sourced
Step 5 Preview
Provider availability
Solar Open 2
Not sourced
Step 5 Preview
Preview · StepFun Open Platform API
StepFun Step 5 Preview model documentationReasoning profile
Solar Open 2
Reasoning
Step 5 Preview
Reasoning
Weight access
Solar Open 2
Open Weight
Step 5 Preview
Pending
License
Solar Open 2
Open Weight
Step 5 Preview
Pending
Release date
Solar Open 2
2026-07-22
Step 5 Preview
2026-09-20
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
- A complete comparable API-rate estimate is not available for both models.
- Context tradeoff
- Both models list 1M.
Run the same representative tasks against both endpoints before changing production traffic.
Benchmark evidence
The full public result ledger is available for audit without forcing a wide desktop table onto a phone.
Browse raw public benchmark evidence30 rows
Agentic
terminalBenchHard
Solar Open 228.3%SourceStep 5 Preview—Not directly comparable
APEX-Agents
Solar Open 216.6%SourceStep 5 Preview37.8%SourceStep 5 Preview leads this result
MCP Atlas
Solar Open 258.2%SourceStep 5 Preview85.6%SourceStep 5 Preview leads this result
Terminal-Bench 2.1
Solar Open 2—Step 5 Preview85.0%SourceNot directly comparable
Terminal-Bench 4.0
Solar Open 2—Step 5 Preview33.30%SourceNot directly comparable
CyberGym
Solar Open 2—Step 5 Preview84.7%SourceNot directly comparable
AutomationBench
Solar Open 2—Step 5 Preview44.0%SourceNot directly comparable
Toolathlon-Verified
Solar Open 2—Step 5 Preview74.1%SourceNot directly comparable
JobBench
Solar Open 2—Step 5 Preview59.0%SourceNot directly comparable
DRACO
Solar Open 2—Step 5 Preview83.3%SourceNot directly comparable
BrowseComp
Solar Open 2—Step 5 Preview88.7%SourceNot directly comparable
Agents' Last Exam
Solar Open 2—Step 5 Preview29.5%SourceNot directly comparable
Coding
LiveCodeBench v6
Solar Open 292.4%SourceStep 5 Preview—Not directly comparable
SWE-bench Verified
Solar Open 270.4%SourceStep 5 Preview—Not directly comparable
DeepSWE
Solar Open 2—Step 5 Preview67.7%SourceNot directly comparable
Terminal-Bench 2.1
Solar Open 2—Step 5 Preview85.0%SourceNot directly comparable
SciCode
Solar Open 2—Step 5 Preview58.9%SourceNot directly comparable
ProgramBench
Solar Open 2—Step 5 Preview80.5%SourceNot directly comparable
sweMarathon
Solar Open 2—Step 5 Preview72.7%SourceNot directly comparable
MLS-Bench Lite
Solar Open 2—Step 5 Preview40.5%SourceNot directly comparable
Reasoning
CritPt
Solar Open 2—Step 5 Preview20.9%SourceNot directly comparable
Multimodal
Knowledge
Instruction following
IFBench
Solar Open 280%SourceStep 5 Preview—Not directly comparable
Math
Questions
Which is better, Solar Open 2 or Step 5 Preview?
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, Solar Open 2 or Step 5 Preview?
Solar Open 2 and Step 5 Preview are not ranked on the public lane for coding, so no winner is named for coding.
Which is better for agentic tasks, Solar Open 2 or Step 5 Preview?
Solar Open 2 and Step 5 Preview are not ranked on the public lane for agentic tasks, so no winner is named for agentic tasks.
Which costs less, Solar Open 2 or Step 5 Preview?
Both models do not have comparable published API token rates, so this page does not name a universal price winner.
Which has the larger context window, Solar Open 2 or Step 5 Preview?
Both models list the same context window, 1M.
Related comparisons
Last updated September 21, 2026
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