Claude Sonnet 4.5 vs Solar Pro4
Wins 1 of 5 areas
Coding
Wins 3 of 5 areas
Agents · Reasoning · Long documents
Solar Pro4 is the stronger all-rounder.Claude Sonnet 4.5 is better at coding.
Scores updated · 20 tests both models report · How we compare
Where each one wins
Tests won in each of the five areas where both have results. Each piece is one test, so a longer bar means more evidence; grey means the two scored within a point of each other.
- ReasoningHard problems that need careful thinking03Solar Pro43 of 3 tests
- AgentsCarrying out multi-step tasks on its own12Solar Pro42 of 4 tests · 1 tie
- Long documentsFinding answers in very long texts01Solar Pro41 of 1 test
- CodingWriting and fixing software31Claude Sonnet 4.53 of 4 tests
- FactsGetting facts right instead of making them up11Even1 each
Long documents rests on a single test.
What it costs
Prices per million tokens, roughly 750,000 words. The bars show the cost of a million tokens read plus a million written.
Solar Pro4 costs 92% less for the same work.
The biggest differences
The three tests each model wins by the widest margin. Scores are out of 100.
Where Solar Pro4 pulls ahead
- Finds hard-to-locate facts by browsing the webBrowseComp+25.1points ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+24.7points ahead
- Very hard expert questions across many subjectsHumanity's Last Exam+11.4points ahead
Where Claude Sonnet 4.5 pulls ahead
- Answers hard knowledge questions correctlyAA-Omniscience · Accuracy+14points ahead
- Fixes real GitHub issues in Python projectsSWE-bench Verified+6.6points ahead
- Customer-service tasks in a simulated bankτ-Bench V3 · Banking+1.2points ahead
Every test, side by side
All 20 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingClaude Sonnet 4.5
- SWE-bench VerifiedClaude Sonnet 4.5 by 6.677.270.6+6.6
- LMArena · WebDevClaude Sonnet 4.5 by 23 rating points13941371+23 rating
- Terminal-Bench 2.1Solar Pro4 by 1.555.857.3+1.5
- SciCodeClaude Sonnet 4.5 by 1.145.744.6+1.1
AgentsSolar Pro4
- BrowseCompSolar Pro4 by 25.124.149.2+25.1
- GDPValSolar Pro4 by 1020.530.5+10
- τ-Bench V3 · BankingClaude Sonnet 4.5 by 1.224.523.3+1.2
- Terminal-Bench 4.0tie00.5tie
ReasoningSolar Pro4
- Humanity's Last ExamSolar Pro4 by 11.417.829.2+11.4
- GPQA DiamondSolar Pro4 by 5.783.489.1+5.7
- CritPtSolar Pro4 by 4.31.15.4+4.3
FactsEven
- AA-Omniscience · Non-hallucinationSolar Pro4 by 24.750.975.6+24.7
- AA-Omniscience · AccuracyClaude Sonnet 4.5 by 1432.918.9+14
Other results6 tests, not counted
Tests outside the eight areas. They are not counted above: several are summary scores built from other tests, or the same test under another name.
- LiveCodeBenchSolar Pro4 by 16.87187.8+16.8
- AA Agentic IndexSolar Pro4 by 16.117.533.6+16.1
- AA IntelligenceSolar Pro4 by 7.520.728.2+7.5
- MMLU-ProClaude Sonnet 4.5 by 1.287.586.3+1.2
- AA-Omnisciencetie-0.1-0.8tie
- Artificial Analysis Coding Indextie52.152.7tie
Questions people ask
Which is better, Claude Sonnet 4.5 or Solar Pro4?
Solar Pro4 wins three of the five areas where both have results: agents, reasoning and long documents. Claude Sonnet 4.5 wins coding. They are level on facts.
Which is better for coding?
Claude Sonnet 4.5. It wins 3 of the 4 coding tests both models report; Solar Pro4 wins 1.
Which is cheaper?
Claude Sonnet 4.5 costs $3.00 per million input tokens and $15.00 per million output tokens; Solar Pro4 costs $0.30 and $1.20. That makes Solar Pro4 about 92% cheaper for the same work.
How do you compare the two?
We use the 20 benchmark tests both models have published scores on. The verdict counts the 14 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 6 are listed but not counted, because several are summary scores or repeat a test. Each score is the one shown on the model's own page.