Claude Sonnet 5 vs Ember-1
Claude Sonnet 5 leads Ember-1 on coding, 57.7 to 52.6 on the Vibe Coding Index, and Claude Sonnet 5 costs 1.5x less per output token ($10.00 vs $15.00 per million). Updated October 21, 2026; 11 benchmarks have a result for both.
vs boards won of 11 shared, 1 tied
Claude Sonnet 5 or Ember-1: which to pick
Pick Claude Sonnet 5 for coding: it scores 57.7 on the Vibe Coding Index against 52.6 for Ember-1.
Pick Ember-1 for a larger context window (1.05M against 1M tokens) and work measured by Terminal-Bench 4 (Vals AI) or Vibe Code Bench (Vals AI), where it leads.
Model AClaude Sonnet 5Anthropic57.7/1006 independent benchmarks$1.87 per solved taskModel BEmber-1Fireworks52.6/1002 independent benchmarksNo cost per solved task
- Shared results
- 11
- Claude Sonnet 5 only
- 110
- Ember-1 only
- 3
- Like-for-like categories
- 3 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
Claude Sonnet 5
Claude Sonnet 5 scores 57.7 against 52.6.
6 and 2 benchmarks behind the scores
Intelligence
AA Intelligence Index
No call
Only Claude Sonnet 5 has a AA Intelligence Index result, 38.2.
Directional only
Agentic work
AA Agentic Index
No call
Only Claude Sonnet 5 has a AA Agentic Index result, 43.6.
Directional only
Reasoning
GPQA Diamond
No call
Only Claude Sonnet 5 has a GPQA Diamond result, 88.9%.
Directional only
Knowledge
MMLU Pro
No call
Only Claude Sonnet 5 has a MMLU Pro result, 87.5%.
Directional only
Web design
Design Arena: websites
No call
Only Claude Sonnet 5 has a Design Arena: websites result, 1274.
Directional only
Long documents
Listed context window
Ember-1
Ember-1 takes 1.05M tokens against 1M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Claude Sonnet 5
Claude Sonnet 5 $0.0070, Ember-1 $0.011 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Claude Sonnet 5 has the number, $1.87.
Directional only
At a glance
- Coding index
- Claude Sonnet 5 57.7 from 6 benchmarks, Ember-1 52.6 from 2 benchmarks.
- Widest category
- Coding, 6.0 points apart on average over 5 shared benchmarks.
- Widest single gap
- Terminal-Bench 4 (Vals AI): Claude Sonnet 5 10.6% against Ember-1 20.7%, 13.5 points apart on a 0 to 100 scale.
- Output price
- Claude Sonnet 5 $10.00 against Ember-1 $15.00 per million output tokens, 1.5x apart.
- Context window
- Claude Sonnet 5 takes 1M 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 Sonnet 5 | Bars | Ember-1 | Ties |
|---|---|---|---|---|
| Coding | 2 | 3 | ||
| Agentic work | 2 | 2 | 1 tie | |
| General | 0 | 1 | ||
| All shared boards | 4 | 6 | 1 tie |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index23
| Benchmark | Claude Sonnet 5 | Ember-1 | Leader |
|---|---|---|---|
| LiveBench coding | 74.7% | Not measured | Only Claude Sonnet 5 measured |
| LMArena WebDev | 1540 | Not measured | Only Claude Sonnet 5 measured |
| AA Coding Index | 71.5 | Not measured | Only Claude Sonnet 5 measured |
| LiveCodeBench (Vals AI) | 82.4% | Not measured | Only Claude Sonnet 5 measured |
| SWE-bench Verified (Vals AI) | 79.6% | Not measured | Only Claude Sonnet 5 measured |
| Terminal-Bench 4 (Vals AI) | 10.6% | 20.7% | Ember-1 |
| Vibe Code Bench (Vals AI) | 81.3% | 83.9% | Ember-1 |
| Code migration (Vals AI) | 44.4% | 32.5% | Claude Sonnet 5 |
| ProgramBench (Vals AI) | 0.0% | Not measured | Only Claude Sonnet 5 measured |
| IOI (Vals AI) | 45.0% | 46.3% | Ember-1 |
| Terminal-Bench 2.1 (Vals AI) | 74.5% | Not measured | Only Claude Sonnet 5 measured |
| Vibe Code Bench 1-100 (Vals AI) | 13.8% | Not measured | Only Claude Sonnet 5 measured |
| SkillsBench (Vals AI) | 46.5% | Not measured | Only Claude Sonnet 5 measured |
| CyberBench (Vals AI) | 70.3% | 69.5% | Claude Sonnet 5 |
| SciCode | 54.3% | Not measured | Only Claude Sonnet 5 measured |
| FrontierCode | 42.7% | Not measured | Only Claude Sonnet 5 measured |
| GSO-Bench | 37.3% | Not measured | Only Claude Sonnet 5 measured |
| WeirdML | 68.8% | Not measured | Only Claude Sonnet 5 measured |
| ALE-Bench | 1463.1 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: coding | 1483 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: software and IT | 1474 | Not measured | Only Claude Sonnet 5 measured |
| LMArena WebDev: React | 1541 | Not measured | Only Claude Sonnet 5 measured |
| LMArena WebDev: HTML | 1527 | Not measured | Only Claude Sonnet 5 measured |
| LMArena WebDev: from an image | 1540 | Not measured | Only Claude Sonnet 5 measured |
| SciCode | 10.7% | Not measured | Only Claude Sonnet 5 measured |
| Neither model has a result on the other 14 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | Claude Sonnet 5 | Ember-1 | Leader |
|---|---|---|---|
| AA Intelligence Index | 38.2 | Not measured | Only Claude Sonnet 5 measured |
| Epoch Capabilities Index | 156.9 | Not measured | Only Claude Sonnet 5 measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index22
| Benchmark | Claude Sonnet 5 | Ember-1 | Leader |
|---|---|---|---|
| AA Agentic Index | 43.6 | Not measured | Only Claude Sonnet 5 measured |
| Design Arena: agents building web apps | 1245 | Not measured | Only Claude Sonnet 5 measured |
| Design Arena: agents building full-stack apps | 1249 | Not measured | Only Claude Sonnet 5 measured |
| Design Arena: agents building mobile apps | 1215 | Not measured | Only Claude Sonnet 5 measured |
| Design Arena: agents building Android apps | 1225 | Not measured | Only Claude Sonnet 5 measured |
| Design Arena: agents building Godot games | 1225 | Not measured | Only Claude Sonnet 5 measured |
| Design Arena: agents building games | 1227 | Not measured | Only Claude Sonnet 5 measured |
| Design Arena: HTML slides | 1218 | Not measured | Only Claude Sonnet 5 measured |
| Design Arena: PowerPoint slides | 1216 | Not measured | Only Claude Sonnet 5 measured |
| Design Arena: spreadsheets | 1021 | Not measured | Only Claude Sonnet 5 measured |
| LiveBench research | 82.8% | Not measured | Only Claude Sonnet 5 measured |
| LiveBench browser | 72.0% | Not measured | Only Claude Sonnet 5 measured |
| LiveBench long agentic | 39.0% | Not measured | Only Claude Sonnet 5 measured |
| SREBench (Vals AI) | 0.4% | Not measured | Only Claude Sonnet 5 measured |
| Finance Agent (Vals AI) | 53.9% | 51.8% | Claude Sonnet 5 |
| Tax Agent Bench (Vals AI) | 29.4% | 31.1% | Ember-1 |
| Legal Research Bench (Vals AI) | 41.8% | 44.7% | Ember-1 |
| Excel Modeling Benchmark (Vals AI) | 66.3% | 63.4% | Claude Sonnet 5 |
| BioMysteryBench (Vals AI) | Not measured | 67.0% | Only Ember-1 measured |
| Terminal-Bench-Science (Vals AI) | 5.7% | 5.7% | Tie |
| Vals Science Index | Not measured | 31.8% | Only Ember-1 measured |
| APEX-Agents | 54.5% | Not measured | Only Claude Sonnet 5 measured |
| Vending-Bench 2 | $6,378 | Not measured | Only Claude Sonnet 5 measured |
| Neither model has a result on the other 18 boards here | |||
ReasoningDirectional onlyPublic boards, shown as published, kept out of the index15 boards, none shared
| Benchmark | Claude Sonnet 5 | Ember-1 | Leader |
|---|---|---|---|
| GPQA Diamond | 88.9% | Not measured | Only Claude Sonnet 5 measured |
| LiveBench reasoning | 88.7% | Not measured | Only Claude Sonnet 5 measured |
| MysteryMechanism (Vals AI) | Not measured | 22.5% | Only Ember-1 measured |
| MMMU Pro (Vals AI) | 83.0% | Not measured | Only Claude Sonnet 5 measured |
| GPQA Diamond (Artificial Analysis run) | 91.1% | Not measured | Only Claude Sonnet 5 measured |
| Humanity's Last Exam (Artificial Analysis run) | 41.3% | Not measured | Only Claude Sonnet 5 measured |
| GPQA Diamond (Epoch AI run) | 90.5% | Not measured | Only Claude Sonnet 5 measured |
| SimpleBench | 60.6% | Not measured | Only Claude Sonnet 5 measured |
| Chess puzzles | 45.0% | Not measured | Only Claude Sonnet 5 measured |
| Mystery game puzzles | 35.0% | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: hard prompts | 1461 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: expert | 1489 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: hard prompts in English | 1464 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Vision: diagrams | 1293 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Vision: homework | 1311 | Not measured | Only Claude Sonnet 5 measured |
| Neither model has a result on the other 7 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index6 boards, none shared
| Benchmark | Claude Sonnet 5 | Ember-1 | Leader |
|---|---|---|---|
| OTIS Mock AIME | 94.7% | Not measured | Only Claude Sonnet 5 measured |
| FrontierMath, tiers 1 to 3 | 65.6% | Not measured | Only Claude Sonnet 5 measured |
| FrontierMath, tier 4 | 29.3% | Not measured | Only Claude Sonnet 5 measured |
| ProofBench | 77.0% | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: math | 1467 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: mathematical work | 1481 | Not measured | Only Claude Sonnet 5 measured |
| Neither model has a result on the other 7 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index11 boards, none shared
| Benchmark | Claude Sonnet 5 | Ember-1 | Leader |
|---|---|---|---|
| MMLU Pro | 87.5% | Not measured | Only Claude Sonnet 5 measured |
| LegalBench (Vals AI) | 83.9% | Not measured | Only Claude Sonnet 5 measured |
| CorpFin (Vals AI) | 67.0% | Not measured | Only Claude Sonnet 5 measured |
| TaxEval (Vals AI) | 75.6% | Not measured | Only Claude Sonnet 5 measured |
| MortgageTax (Vals AI) | 70.0% | Not measured | Only Claude Sonnet 5 measured |
| MedCode (Vals AI) | 47.5% | Not measured | Only Claude Sonnet 5 measured |
| SimpleQA Verified | 33.7% | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: science | 1460 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: medicine and healthcare | 1442 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: legal and government | 1454 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: business and finance | 1436 | Not measured | Only Claude Sonnet 5 measured |
| Neither model has a result on the other 7 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index9 boards, none shared
| Benchmark | Claude Sonnet 5 | Ember-1 | Leader |
|---|---|---|---|
| Design Arena: websites | 1274 | Not measured | Only Claude Sonnet 5 measured |
| Design Arena: UI components | 1280 | Not measured | Only Claude Sonnet 5 measured |
| Design Arena: game dev | 1278 | Not measured | Only Claude Sonnet 5 measured |
| Design Arena: data viz | 1251 | Not measured | Only Claude Sonnet 5 measured |
| Design Arena: 3D | 1261 | Not measured | Only Claude Sonnet 5 measured |
| Design Arena: all code categories | 1276 | Not measured | Only Claude Sonnet 5 measured |
| Design Arena: SVG | 1193 | Not measured | Only Claude Sonnet 5 measured |
| Design Arena: ASCII art | 1207 | Not measured | Only Claude Sonnet 5 measured |
| LiveBench design | 82.0% | Not measured | Only Claude Sonnet 5 measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Claude Sonnet 5 | Ember-1 | Leader |
|---|---|---|---|
| LiveBench data analysis | 71.7% | Not measured | Only Claude Sonnet 5 measured |
| Public Benefits Bench (Vals AI) | 66.0% | 66.2% | Ember-1 |
| SAGE (Vals AI) | 48.9% | Not measured | Only Claude Sonnet 5 measured |
| MedScribe (Vals AI) | 76.0% | Not measured | Only Claude Sonnet 5 measured |
| Vals Multimodal Index | 68.8% | Not measured | Only Claude Sonnet 5 measured |
| Long context reasoning (AA-LCR) | 82.0% | Not measured | Only Claude Sonnet 5 measured |
| DTBench | 92.5% | Not measured | Only Claude Sonnet 5 measured |
| LMCA | 50.0% | Not measured | Only Claude Sonnet 5 measured |
| Surface Evolver Bench | 60.0% | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text | 1442 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: instruction following | 1452 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: creative writing | 1416 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Vision | 1273 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: English | 1450 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: non-English | 1431 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: Chinese | 1478 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: German | 1442 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: Japanese | 1422 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: Korean | 1412 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: French | 1463 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: Spanish | 1438 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: Russian | 1450 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: Polish | 1425 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: multi-turn | 1453 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: longer queries | 1462 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: writing and language | 1436 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: entertainment and media | 1411 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Vision: English | 1275 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Vision: Chinese | 1331 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Vision: reading text | 1288 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Vision: humor | 1261 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Vision: creative writing | 1246 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Document | 1466 | Not measured | Only Claude Sonnet 5 measured |
| Neither model has a result on the other 13 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Claude Sonnet 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 Sonnet 5$0.0070Fits in one request
Ember-1$0.011Fits in one request
Claude Sonnet 5 costs less
Repository review
50K input + 3K output tokens
Claude Sonnet 5$0.130Fits in one request
Ember-1$0.195Fits in one request
Claude Sonnet 5 costs less
Agent loop
200K input + 10K output tokens
Claude Sonnet 5$0.500Fits in one request
Ember-1$0.750Fits in one request
Claude Sonnet 5 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 Sonnet 5 | Fireworks Ember-1 |
|---|---|---|
| Maker | Anthropic | Fireworks |
| Weights | No public weights listed | No public weights listed |
| Released | June 30, 2026 | September 24, 2026 |
| Context window | 1M | 1.05M |
| Input $/Mtok | $2.00 | $3.00 |
| Output $/Mtok | $10.00 | $15.00 |
| Coding index | 57.7 | 52.6 |
| Independent measurements behind it | 6 | 2 |
| Cost per solved task | $1.87 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Sonnet 5 better than Ember-1 for coding?
Pick Claude Sonnet 5 for coding: it scores 57.7 on the Vibe Coding Index against 52.6 for Ember-1. Pick Ember-1 for a larger context window (1.05M against 1M tokens) and work measured by Terminal-Bench 4 (Vals AI) or Vibe Code Bench (Vals AI), where it leads.
Which is cheaper, Claude Sonnet 5 or Ember-1?
Claude Sonnet 5 costs $2.00 per million input tokens and $10.00 per million output tokens; Ember-1 costs $3.00 and $15.00. Cost per solved task is known for Claude Sonnet 5 only.
Which has the bigger context window, Claude Sonnet 5 or Ember-1?
Ember-1, with 1.05M tokens against 1M.
How many benchmarks is the Claude Sonnet 5 vs Ember-1 comparison based on?
11 benchmarks have a result for both models as of October 21, 2026. Claude Sonnet 5's coding index rests on 6 independent benchmarks and Ember-1's on 2. Where only one model has a result, the page says so instead of naming a winner.