Model Comparison

Jamba 1.5 Large vs Phi 4 Reasoning Plus

Phi 4 Reasoning Plus significantly outperforms across most benchmarks.

Want to compare interactively?Try the playground

Performance Benchmarks

Comparative analysis across standard metrics

3 benchmarks

Jamba 1.5 Large outperforms in 0 benchmarks, while Phi 4 Reasoning Plus is better at 3 benchmarks (Arena Hard, GPQA, MMLU-Pro).

Phi 4 Reasoning Plus significantly outperforms across most benchmarks.

Wed Apr 29 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Cost data unavailable.

Lowest available price from all providers
Wed Apr 29 2026 • llm-stats.com
AI21 Labs
Jamba 1.5 Large
Input tokens$2.00
Output tokens$8.00
Best providerAWS Bedrock
Microsoft
Phi 4 Reasoning Plus
Input tokens$0.00
Output tokens$0.00
Best providerUnknown Organization
Notice missing or incorrect data?Start an Issue→

Model Size

Parameter count comparison

384.0B diff

Jamba 1.5 Large has 384.0B more parameters than Phi 4 Reasoning Plus, making it 2742.9% larger.

AI21 Labs
Jamba 1.5 Large
398.0Bparameters
Microsoft
Phi 4 Reasoning Plus
14.0Bparameters
398.0B
Jamba 1.5 Large
14.0B
Phi 4 Reasoning Plus

Context Window

Maximum input and output token capacity

Only Jamba 1.5 Large specifies input context (256,000 tokens). Only Jamba 1.5 Large specifies output context (256,000 tokens).

AI21 Labs
Jamba 1.5 Large
Input256,000 tokens
Output256,000 tokens
Microsoft
Phi 4 Reasoning Plus
Input- tokens
Output- tokens
Wed Apr 29 2026 • llm-stats.com

License

Usage and distribution terms

Jamba 1.5 Large is licensed under Jamba Open Model License, while Phi 4 Reasoning Plus uses MIT.

License differences may affect how you can use these models in commercial or open-source projects.

Jamba 1.5 Large

Jamba Open Model License

Open weights

Phi 4 Reasoning Plus

MIT

Open weights

Release Timeline

When each model was launched

Jamba 1.5 Large was released on 2024-08-22, while Phi 4 Reasoning Plus was released on 2025-04-30.

Phi 4 Reasoning Plus is 8 months newer than Jamba 1.5 Large.

Jamba 1.5 Large

Aug 22, 2024

1.7 years ago

Phi 4 Reasoning Plus

Apr 30, 2025

12 months ago

8mo newer

Knowledge Cutoff

When training data ends

Jamba 1.5 Large has a knowledge cutoff of 2024-03-05, while Phi 4 Reasoning Plus has a cutoff of 2025-03-01.

Phi 4 Reasoning Plus has more recent training data (up to 2025-03-01), making it potentially better informed about events through that date compared to Jamba 1.5 Large (2024-03-05).

Jamba 1.5 Large

Mar 2024

Phi 4 Reasoning Plus

Mar 2025

1 yr newer

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

AI21 Labs
Larger context window (256,000 tokens)
Microsoft
Higher Arena Hard score (79.0% vs 65.4%)
Higher GPQA score (68.9% vs 36.9%)
Higher MMLU-Pro score (76.0% vs 53.5%)

Detailed Comparison

AI Model Comparison Table
Feature
AI21 Labs
Jamba 1.5 Large
Microsoft
Phi 4 Reasoning Plus

FAQ

Common questions about Jamba 1.5 Large vs Phi 4 Reasoning Plus

Phi 4 Reasoning Plus significantly outperforms across most benchmarks. Jamba 1.5 Large is made by AI21 Labs and Phi 4 Reasoning Plus is made by Microsoft. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.
Jamba 1.5 Large scores ARC-C: 93.0%, GSM8k: 87.0%, MMLU: 81.2%, Arena Hard: 65.4%, TruthfulQA: 58.3%. Phi 4 Reasoning Plus scores FlenQA: 97.9%, HumanEval+: 92.3%, IFEval: 84.9%, OmniMath: 81.9%, AIME 2024: 81.3%.
Jamba 1.5 Large supports 256K tokens and Phi 4 Reasoning Plus supports an unknown number of tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.
Key differences include licensing (Jamba Open Model License vs MIT). See the full comparison above for benchmark-by-benchmark results.
Jamba 1.5 Large is developed by AI21 Labs and Phi 4 Reasoning Plus is developed by Microsoft.