Ember-1 vs Hy4 preview
Ember-1 leads Hy4 preview on coding, 52.6 to 44.3 on the Vibe Coding Index, and Hy4 preview costs 6.0x less per output token ($2.501 vs $15.00 per million). Updated October 22, 2026; 12 benchmarks have a result for both.
Ember-1 or Hy4 preview: which to pick
Pick Ember-1 for coding: it scores 52.6 on the Vibe Coding Index against 44.3 for Hy4 preview, though on 2 benchmarks against 3.
Pick Hy4 preview for output tokens 6.0x cheaper ($2.501 vs $15.00 per million) and work measured by Code migration (Vals AI) or IOI (Vals AI), where it leads.
- Shared results
- 12
- Ember-1 only
- 2
- Hy4 preview only
- 12
- 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
Ember-1
Ember-1 scores 52.6 against 44.3.
2 and 3 benchmarks behind the scores
General
Vals Index
No call
Only Hy4 preview has a Vals Index result, 53.2%.
Directional only
Long documents
Listed context window
No call
Both take 1.05M tokens.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Hy4 preview
Ember-1 $0.011, Hy4 preview $0.0021 per turn.
List prices
At a glance
- Coding index
- Ember-1 52.6 from 2 benchmarks, Hy4 preview 44.3 from 3 benchmarks.
- Widest category
- Coding, 11.1 points apart on average over 5 shared benchmarks.
- Widest single gap
- Terminal-Bench 4 (Vals AI): Ember-1 20.7% against Hy4 preview 8.1%, 16.8 points apart on a 0 to 100 scale.
- Output price
- Ember-1 $15.00 against Hy4 preview $2.501 per million output tokens, 6.0x apart.
- Context window
- Both take 1.05M tokens.
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 | Ember-1 | Bars | Hy4 preview | Ties |
|---|---|---|---|---|
| Coding | 3 | 2 | ||
| Agentic work | 2 | 4 | ||
| General | 0 | 1 | ||
| All shared boards | 5 | 7 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index32
| Benchmark | Ember-1 | Hy4 preview | Leader |
|---|---|---|---|
| LMArena WebDev | Not measured | 1631 | Only Hy4 preview measured |
| Terminal-Bench 4 (Vals AI) | 20.7% | 8.1% | Ember-1 |
| Vibe Code Bench (Vals AI) | 83.9% | 77.5% | Ember-1 |
| Code migration (Vals AI) | 32.5% | 47.4% | Hy4 preview |
| ProgramBench (Vals AI) | Not measured | 0.0% | Only Hy4 preview measured |
| IOI (Vals AI) | 46.3% | 59.3% | Hy4 preview |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 55.1% | Only Hy4 preview measured |
| CyberBench (Vals AI) | 69.5% | 65.4% | Ember-1 |
| LMArena WebDev: React | Not measured | 1653 | Only Hy4 preview measured |
| LMArena WebDev: HTML | Not measured | 1620 | Only Hy4 preview measured |
| Neither model has a result on the other 29 boards here | |||
IntelligenceNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Ember-1 | Hy4 preview | Leader |
|---|---|---|---|
| Neither model has a result on 2 boards here | |||
Agentic workLike-for-likePublic boards, shown as published, kept out of the index24
| Benchmark | Ember-1 | Hy4 preview | Leader |
|---|---|---|---|
| SREBench (Vals AI) | Not measured | 2.3% | Only Hy4 preview measured |
| Finance Agent (Vals AI) | 51.8% | 55.1% | Hy4 preview |
| Tax Agent Bench (Vals AI) | 31.1% | 32.6% | Hy4 preview |
| Legal Research Bench (Vals AI) | 44.7% | 45.2% | Hy4 preview |
| Harvey's Legal Agent Benchmark (Vals AI) | Not measured | 8.8% | Only Hy4 preview measured |
| Excel Modeling Benchmark (Vals AI) | 63.4% | 58.1% | Ember-1 |
| BioMysteryBench (Vals AI) | 67.0% | 69.3% | Hy4 preview |
| Terminal-Bench-Science (Vals AI) | 5.7% | 1.4% | Ember-1 |
| Vals Science Index | 31.8% | Not measured | Only Ember-1 measured |
| Neither model has a result on the other 32 boards here | |||
ReasoningDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | Ember-1 | Hy4 preview | Leader |
|---|---|---|---|
| MysteryMechanism (Vals AI) | 22.5% | Not measured | Only Ember-1 measured |
| Neither model has a result on the other 21 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | Ember-1 | Hy4 preview | Leader |
|---|---|---|---|
| ProofBench | Not measured | 75.0% | Only Hy4 preview measured |
| Neither model has a result on the other 12 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | Ember-1 | Hy4 preview | Leader |
|---|---|---|---|
| LegalBench (Vals AI) | Not measured | 83.8% | Only Hy4 preview measured |
| MedCode (Vals AI) | Not measured | 43.3% | Only Hy4 preview measured |
| Neither model has a result on the other 16 boards here | |||
Web designNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Ember-1 | Hy4 preview | Leader |
|---|---|---|---|
| Neither model has a result on 9 boards here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Ember-1 | Hy4 preview | Leader |
|---|---|---|---|
| Vals Index | Not measured | 53.2% | Only Hy4 preview measured |
| Public Benefits Bench (Vals AI) | 66.2% | 68.6% | Hy4 preview |
| MedScribe (Vals AI) | Not measured | 83.6% | Only Hy4 preview measured |
| Neither model has a result on the other 43 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Ember-1 | Hy4 preview | 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
Hy4 preview costs less
Repository review
50K input + 3K output tokens
Hy4 preview costs less
Agent loop
200K input + 10K output tokens
Hy4 preview 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 | Fireworks Ember-1 | Tencent Hy4 preview |
|---|---|---|
| Maker | Fireworks | Tencent |
| Weights | No public weights listed | Open weights |
| Released | September 24, 2026 | August 28, 2026 |
| Context window | 1.05M | 1.05M |
| Input $/Mtok | $3.00 | $0.834 |
| Output $/Mtok | $15.00 | $2.501 |
| Coding index | 52.6 | 44.3 |
| Independent measurements behind it | 2 | 3 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Ember-1 better than Hy4 preview for coding?
Pick Ember-1 for coding: it scores 52.6 on the Vibe Coding Index against 44.3 for Hy4 preview, though on 2 benchmarks against 3. Pick Hy4 preview for output tokens 6.0x cheaper ($2.501 vs $15.00 per million) and work measured by Code migration (Vals AI) or IOI (Vals AI), where it leads.
Which is cheaper, Ember-1 or Hy4 preview?
Ember-1 costs $3.00 per million input tokens and $15.00 per million output tokens; Hy4 preview costs $0.834 and $2.501. Cost per solved task is known for neither of them.
Which has the bigger context window, Ember-1 or Hy4 preview?
Neither: both take 1.05M tokens.
How many benchmarks is the Ember-1 vs Hy4 preview comparison based on?
12 benchmarks have a result for both models as of October 22, 2026. Ember-1's coding index rests on 2 independent benchmarks and Hy4 preview's on 3. Where only one model has a result, the page says so instead of naming a winner.