Claude Opus 4.5 vs Ember-1
Ember-1 leads Claude Opus 4.5 on coding, 52.6 to 44.0 on the Vibe Coding Index, and Ember-1 costs 1.7x less per output token ($15.00 vs $25.00 per million). Updated October 21, 2026; 1 benchmarks have a result for both.
vs boards won of 1 shared
Claude Opus 4.5 or Ember-1: which to pick
Pick Ember-1 for coding: it scores 52.6 on the Vibe Coding Index against 44.0 for Claude Opus 4.5, though on 2 benchmarks against 3.
Claude Opus 4.5 is neither cheaper nor larger in context, and leads no benchmark both models were measured on.
Model AClaude Opus 4.5Anthropic44.0/1003 independent benchmarks$1.37 per solved taskModel BEmber-1Fireworks52.6/1002 independent benchmarksNo cost per solved task
- Shared results
- 1
- Claude Opus 4.5 only
- 107
- Ember-1 only
- 13
- Like-for-like categories
- 1 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
Ember-1
Ember-1 scores 52.6 against 44.0.
3 and 2 benchmarks behind the scores
Intelligence
AA Intelligence Index
No call
Only Claude Opus 4.5 has a AA Intelligence Index result, 29.1.
Directional only
Reasoning
GPQA Diamond
No call
Only Claude Opus 4.5 has a GPQA Diamond result, 85.9%.
Directional only
Math
AIME
No call
Only Claude Opus 4.5 has a AIME result, 95.4%.
Directional only
Knowledge
MMLU Pro
No call
Only Claude Opus 4.5 has a MMLU Pro result, 87.3%.
Directional only
Web design
Design Arena: websites
No call
Only Claude Opus 4.5 has a Design Arena: websites result, 1247.
Directional only
Long documents
Listed context window
Ember-1
Ember-1 takes 1.05M tokens against 200K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Ember-1
Claude Opus 4.5 $0.018, Ember-1 $0.011 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Claude Opus 4.5 has the number, $1.37.
Directional only
At a glance
- Coding index
- Claude Opus 4.5 44.0 from 3 benchmarks, Ember-1 52.6 from 2 benchmarks.
- Widest category
- Coding, 63.2 points apart on average over 1 shared benchmark.
- Widest single gap
- Vibe Code Bench (Vals AI): Claude Opus 4.5 20.6% against Ember-1 83.9%, 63.2 points apart on a 0 to 100 scale.
- Output price
- Claude Opus 4.5 $25.00 against Ember-1 $15.00 per million output tokens, 1.7x apart.
- Context window
- Claude Opus 4.5 takes 200K tokens, Ember-1 1.05M.
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 | Claude Opus 4.5 | Bars | Ember-1 | Ties |
|---|---|---|---|---|
| Coding | 0 | 1 | ||
| All shared boards | 0 | 1 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index01
| Benchmark | Claude Opus 4.5 | Ember-1 | Leader |
|---|---|---|---|
| SWE-bench Verified | 79.2% | Not measured | Only Claude Opus 4.5 measured |
| SWE-bench (full test set) | 52.6% | Not measured | Only Claude Opus 4.5 measured |
| SWE-bench Multilingual | 70.7% | Not measured | Only Claude Opus 4.5 measured |
| LMArena WebDev | 1494 | Not measured | Only Claude Opus 4.5 measured |
| LiveCodeBench (Vals AI) | 83.7% | Not measured | Only Claude Opus 4.5 measured |
| SWE-bench Verified (Vals AI) | 76.4% | Not measured | Only Claude Opus 4.5 measured |
| Terminal-Bench 4 (Vals AI) | Not measured | 20.7% | Only Ember-1 measured |
| Vibe Code Bench (Vals AI) | 20.6% | 83.9% | Ember-1 |
| Code migration (Vals AI) | Not measured | 32.5% | Only Ember-1 measured |
| IOI (Vals AI) | Not measured | 46.3% | Only Ember-1 measured |
| CyberBench (Vals AI) | Not measured | 69.5% | Only Ember-1 measured |
| LiveCodeBench (Artificial Analysis run) | 87.1% | Not measured | Only Claude Opus 4.5 measured |
| Terminal-Bench Hard (Artificial Analysis run) | 47.0% | Not measured | Only Claude Opus 4.5 measured |
| Terminal-Bench | 63.1% | Not measured | Only Claude Opus 4.5 measured |
| GSO-Bench | 26.5% | Not measured | Only Claude Opus 4.5 measured |
| WeirdML | 63.7% | Not measured | Only Claude Opus 4.5 measured |
| Cybench | 82.0% | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: coding | 1503 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: software and IT | 1483 | Not measured | Only Claude Opus 4.5 measured |
| LMArena WebDev: React | 1478 | Not measured | Only Claude Opus 4.5 measured |
| LMArena WebDev: HTML | 1510 | Not measured | Only Claude Opus 4.5 measured |
| Neither model has a result on the other 18 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | Claude Opus 4.5 | Ember-1 | Leader |
|---|---|---|---|
| AA Intelligence Index | 29.1 | Not measured | Only Claude Opus 4.5 measured |
| Epoch Capabilities Index | 150.1 | Not measured | Only Claude Opus 4.5 measured |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index20 boards, none shared
| Benchmark | Claude Opus 4.5 | Ember-1 | Leader |
|---|---|---|---|
| Design Arena: agents building web apps | 1159 | Not measured | Only Claude Opus 4.5 measured |
| Design Arena: agents building full-stack apps | 1156 | Not measured | Only Claude Opus 4.5 measured |
| Design Arena: agents building mobile apps | 1189 | Not measured | Only Claude Opus 4.5 measured |
| Design Arena: agents building Android apps | 1175 | Not measured | Only Claude Opus 4.5 measured |
| Finance Agent (Vals AI) | Not measured | 51.8% | Only Ember-1 measured |
| Tax Agent Bench (Vals AI) | Not measured | 31.1% | Only Ember-1 measured |
| Legal Research Bench (Vals AI) | Not measured | 44.7% | Only Ember-1 measured |
| Excel Modeling Benchmark (Vals AI) | Not measured | 63.4% | Only Ember-1 measured |
| BioMysteryBench (Vals AI) | Not measured | 67.0% | Only Ember-1 measured |
| Terminal-Bench-Science (Vals AI) | Not measured | 5.7% | Only Ember-1 measured |
| Vals Science Index | Not measured | 31.8% | Only Ember-1 measured |
| τ²-Bench Telecom | 89.5% | Not measured | Only Claude Opus 4.5 measured |
| METR time horizons | 75.0% | Not measured | Only Claude Opus 4.5 measured |
| Remote Labor Index | 3.8% | Not measured | Only Claude Opus 4.5 measured |
| GDPval | 45.5% | Not measured | Only Claude Opus 4.5 measured |
| BALROG | 43.5% | Not measured | Only Claude Opus 4.5 measured |
| DeepResearch Bench | 54.8% | Not measured | Only Claude Opus 4.5 measured |
| OSWorld | 66.3% | Not measured | Only Claude Opus 4.5 measured |
| Vending-Bench 2 | $4,967 | Not measured | Only Claude Opus 4.5 measured |
| Berkeley Function Calling Leaderboard (BFCL) | 77.5% | Not measured | Only Claude Opus 4.5 measured |
| Neither model has a result on the other 21 boards here | |||
ReasoningDirectional onlyPublic boards, shown as published, kept out of the index17 boards, none shared
| Benchmark | Claude Opus 4.5 | Ember-1 | Leader |
|---|---|---|---|
| GPQA Diamond | 85.9% | Not measured | Only Claude Opus 4.5 measured |
| MysteryMechanism (Vals AI) | Not measured | 22.5% | Only Ember-1 measured |
| MMMU Pro (Vals AI) | 83.0% | Not measured | Only Claude Opus 4.5 measured |
| GPQA Diamond (Artificial Analysis run) | 86.6% | Not measured | Only Claude Opus 4.5 measured |
| Humanity's Last Exam (Artificial Analysis run) | 30.1% | Not measured | Only Claude Opus 4.5 measured |
| GPQA Diamond (Epoch AI run) | 86.0% | Not measured | Only Claude Opus 4.5 measured |
| ARC-AGI | 80.0% | Not measured | Only Claude Opus 4.5 measured |
| ARC-AGI-2 | 37.6% | Not measured | Only Claude Opus 4.5 measured |
| SimpleBench | 62.0% | Not measured | Only Claude Opus 4.5 measured |
| Chess puzzles | 14.0% | Not measured | Only Claude Opus 4.5 measured |
| Mystery game puzzles | 22.0% | Not measured | Only Claude Opus 4.5 measured |
| EBR-bench | 14.3% | Not measured | Only Claude Opus 4.5 measured |
| VPCT | 40.0% | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: hard prompts | 1476 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: expert | 1487 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: hard prompts in English | 1482 | Not measured | Only Claude Opus 4.5 measured |
| Kagi LLM Benchmark | 80.2% | Not measured | Only Claude Opus 4.5 measured |
| Neither model has a result on the other 5 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index10 boards, none shared
| Benchmark | Claude Opus 4.5 | Ember-1 | Leader |
|---|---|---|---|
| AIME | 95.4% | Not measured | Only Claude Opus 4.5 measured |
| MGSM (Vals AI) | 95.2% | Not measured | Only Claude Opus 4.5 measured |
| AA Math Index | 91.3 | Not measured | Only Claude Opus 4.5 measured |
| AIME 2025 (Artificial Analysis run) | 91.3% | Not measured | Only Claude Opus 4.5 measured |
| OTIS Mock AIME | 86.1% | Not measured | Only Claude Opus 4.5 measured |
| FrontierMath, tiers 1 to 3 | 34.4% | Not measured | Only Claude Opus 4.5 measured |
| FrontierMath, tier 4 | 4.9% | Not measured | Only Claude Opus 4.5 measured |
| ProofBench | 36.0% | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: math | 1463 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: mathematical work | 1468 | Not measured | Only Claude Opus 4.5 measured |
| Neither model has a result on the other 3 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index16 boards, none shared
| Benchmark | Claude Opus 4.5 | Ember-1 | Leader |
|---|---|---|---|
| MMLU Pro | 87.3% | Not measured | Only Claude Opus 4.5 measured |
| LegalBench (Vals AI) | 84.6% | Not measured | Only Claude Opus 4.5 measured |
| CaseLaw (Vals AI) | 62.6% | Not measured | Only Claude Opus 4.5 measured |
| CorpFin (Vals AI) | 65.1% | Not measured | Only Claude Opus 4.5 measured |
| TaxEval (Vals AI) | 74.9% | Not measured | Only Claude Opus 4.5 measured |
| MortgageTax (Vals AI) | 68.7% | Not measured | Only Claude Opus 4.5 measured |
| MedQA (Vals AI) | 95.9% | Not measured | Only Claude Opus 4.5 measured |
| MedCode (Vals AI) | 49.2% | Not measured | Only Claude Opus 4.5 measured |
| MMLU Pro (Artificial Analysis run) | 89.5% | Not measured | Only Claude Opus 4.5 measured |
| SimpleQA Verified | 45.7% | Not measured | Only Claude Opus 4.5 measured |
| GeoBench | 75.0% | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: science | 1454 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: medicine and healthcare | 1444 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: legal and government | 1459 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: business and finance | 1448 | Not measured | Only Claude Opus 4.5 measured |
| FACTS Benchmark Suite | 43.9% | Not measured | Only Claude Opus 4.5 measured |
| Neither model has a result on the other 2 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index8 boards, none shared
| Benchmark | Claude Opus 4.5 | Ember-1 | Leader |
|---|---|---|---|
| Design Arena: websites | 1247 | Not measured | Only Claude Opus 4.5 measured |
| Design Arena: UI components | 1238 | Not measured | Only Claude Opus 4.5 measured |
| Design Arena: game dev | 1229 | Not measured | Only Claude Opus 4.5 measured |
| Design Arena: data viz | 1243 | Not measured | Only Claude Opus 4.5 measured |
| Design Arena: 3D | 1214 | Not measured | Only Claude Opus 4.5 measured |
| Design Arena: all code categories | 1242 | Not measured | Only Claude Opus 4.5 measured |
| Design Arena: SVG | 1181 | Not measured | Only Claude Opus 4.5 measured |
| Design Arena: ASCII art | 1190 | Not measured | Only Claude Opus 4.5 measured |
| Neither model has a result on the other 1 board here | |||
GeneralDirectional onlyPublic boards, shown as published, kept out of the index27 boards, none shared
| Benchmark | Claude Opus 4.5 | Ember-1 | Leader |
|---|---|---|---|
| Public Benefits Bench (Vals AI) | Not measured | 66.2% | Only Ember-1 measured |
| SAGE (Vals AI) | 52.1% | Not measured | Only Claude Opus 4.5 measured |
| MedScribe (Vals AI) | 85.3% | Not measured | Only Claude Opus 4.5 measured |
| IFBench | 58.0% | Not measured | Only Claude Opus 4.5 measured |
| Long context reasoning (AA-LCR) | 77.3% | Not measured | Only Claude Opus 4.5 measured |
| DTBench | 89.9% | Not measured | Only Claude Opus 4.5 measured |
| LMCA | 44.5% | Not measured | Only Claude Opus 4.5 measured |
| CL-bench | 21.1% | Not measured | Only Claude Opus 4.5 measured |
| Furniture assembly | 28.3% | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text | 1451 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: instruction following | 1478 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: creative writing | 1445 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: English | 1461 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: non-English | 1438 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: Chinese | 1470 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: German | 1449 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: Japanese | 1417 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: Korean | 1424 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: French | 1471 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: Spanish | 1457 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: Russian | 1447 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: Polish | 1439 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: multi-turn | 1466 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: longer queries | 1479 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: writing and language | 1452 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: entertainment and media | 1434 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Document | 1462 | Not measured | Only Claude Opus 4.5 measured |
| Neither model has a result on the other 19 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Claude Opus 4.5 | Ember-1 | 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
Claude Opus 4.5$0.018Fits in one request
Ember-1$0.011Fits in one request
Ember-1 costs less
Repository review
50K input + 3K output tokens
Claude Opus 4.5$0.325Fits in one request
Ember-1$0.195Fits in one request
Ember-1 costs less
Agent loop
200K input + 10K output tokens
Claude Opus 4.5$1.25Exceeds the context window
Ember-1$0.750Fits in one request
Ember-1 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 | Anthropic Claude Opus 4.5 | Fireworks Ember-1 |
|---|---|---|
| Maker | Anthropic | Fireworks |
| Weights | No public weights listed | No public weights listed |
| Released | November 24, 2025 | September 24, 2026 |
| Context window | 200K | 1.05M |
| Input $/Mtok | $5.00 | $3.00 |
| Output $/Mtok | $25.00 | $15.00 |
| Coding index | 44.0 | 52.6 |
| Independent measurements behind it | 3 | 2 |
| Cost per solved task | $1.37 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Opus 4.5 better than Ember-1 for coding?
Pick Ember-1 for coding: it scores 52.6 on the Vibe Coding Index against 44.0 for Claude Opus 4.5, though on 2 benchmarks against 3. Claude Opus 4.5 is neither cheaper nor larger in context, and leads no benchmark both models were measured on.
Which is cheaper, Claude Opus 4.5 or Ember-1?
Claude Opus 4.5 costs $5.00 per million input tokens and $25.00 per million output tokens; Ember-1 costs $3.00 and $15.00. Cost per solved task is known for Claude Opus 4.5 only.
Which has the bigger context window, Claude Opus 4.5 or Ember-1?
Ember-1, with 1.05M tokens against 200K.
How many benchmarks is the Claude Opus 4.5 vs Ember-1 comparison based on?
1 benchmarks have a result for both models as of October 21, 2026. Claude Opus 4.5's coding index rests on 3 independent benchmarks and Ember-1's on 2. Where only one model has a result, the page says so instead of naming a winner.