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Comparison · 2 models · Updated Oct 4, 2026

GPT-5.1 Codex Max vs Jamba Large

GPT-5.1 Codex Max comes out ahead, 42 to 30 on our weighted score, and it is the cheaper option too.

  1. Our pick

    OpenAI

    GPT-5.1 Codex Max

    Released Nov 13, 2025

    42/100
    • ECI—
    • Price$1.25 / $10.00
    • Context400K
    Full specs Remove GPT-5.1 Codex Max

  2. AI21 Labs

    Jamba Large

    Released Jul 1, 2025

    30/100
    • ECI—
    • Price$2.00 / $8.00
    • Context256K
    Full specs Remove Jamba Large

  3. Add a model

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01 — Verdict

GPT-5.1 Codex Max is our pick

GPT-5.1 Codex Max is the better all-round choice, scoring 42/100 against Jamba Large (30). It leads on inputs & features and context window. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.

  • CapabilityNot enough dataNo independent benchmark covers every model here yet
  • Lowest priceGPT-5.1 Codex MaxGPT-5.1 Codex Max $3.44 · Jamba Large $3.50 per 1M tokens (3:1 blend)
  • Longest contextGPT-5.1 Codex MaxGPT-5.1 Codex Max 400,000 · Jamba Large 256,000 tokens
  • Widest inputsGPT-5.1 Codex MaxGPT-5.1 Codex Max: Text, Images · Jamba Large: Text
  • Self-hostingJamba LargePublishes downloadable weights
How the score is built
MeasureWeightGPT-5.1 Codex MaxJamba Large
Price50%2424
Inputs & features30%7035
Context window20%4436
Overall100%42/10030/100

Left out because at least one model lacks the data: capability. The remaining weights were rescaled.

02 — Side by side

Every spec in one table

Highlighted cells lead their row. Dashes mean the data is not published.

GPT-5.1 Codex Max vs Jamba Large specifications side by side
SpecificationGPT-5.1 Codex MaxOpenAIJamba LargeAI21 Labs
Capability
Capabilities Index (ECI)——
ECI rank——
Price per million tokens
Input$1.25 (best)$2.00
Output$10.00$8.00 (best)
Cached input——
Blended (3:1)$3.44 (best)$3.50
Long-context rateSame rateSame rate
Price sourceMedian of 8 providersOfficial AI21 Labs API
Limits
Context window400,000 tokens (best)256,000 tokens
Max output128,000 tokens (best)4,096 tokens
Inputs and features
TextYesYes
ImagesYesNo
PDFsNoNo
AudioNoNo
VideoNoNo
ReasoningYesNo
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryOpen
API model ID—jamba-large
API providers8 (best)1
ReleasedNov 13, 2025Jul 1, 2025
Knowledge cutoffSep 30, 2024Aug 22, 2024
03 — Cost

What would a month cost?

Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.

  • GPT-5.1 Codex Max$32.50
  • Jamba Large$36.00
04 — Questions

Which should you choose?

Which is better: GPT-5.1 Codex Max or Jamba Large?

GPT-5.1 Codex Max is the better all-round choice, scoring 42/100 against Jamba Large (30). It leads on inputs & features and context window. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.

Which is cheaper, GPT-5.1 Codex Max or Jamba Large?

GPT-5.1 Codex Max is cheaper at $1.25 input / $10.00 output per million tokens (median across 8 API providers). Jamba Large costs $2.00 input / $8.00 output per million tokens (official AI21 Labs API price). At a typical mix of three input tokens to one output token, that is $3.44 per million tokens for GPT-5.1 Codex Max versus $3.50 for Jamba Large (1× as much).

Which scores higher on benchmarks?

There is no independent benchmark that covers both models yet. GPT-5.1 Codex Max has not been scored yet and Jamba Large has not been scored yet.

Which is better for coding?

There are no published SWE-bench Verified results for GPT-5.1 Codex Max and Jamba Large yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Both support tool calling for agent workflows.

Which has the bigger context window?

GPT-5.1 Codex Max has the largest context window at 400,000 tokens, against 256,000 for Jamba Large. Maximum output per response: GPT-5.1 Codex Max up to 128,000, Jamba Large up to 4,096 tokens.

Which can read images, PDFs, audio or video?

GPT-5.1 Codex Max accepts text and images; Jamba Large accepts text. GPT-5.1 Codex Max handles the widest range of inputs.

Are any of these open source?

Jamba Large publishes its weights and can be self-hosted; GPT-5.1 Codex Max is proprietary.

Which is newer?

GPT-5.1 Codex Max is the newest, released Nov 13, 2025. Jamba Large came out Jul 1, 2025. Knowledge cutoff: GPT-5.1 Codex Max Sep 30, 2024, Jamba Large Aug 22, 2024.

How do you decide the winner?

Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.

05 — Keep comparing

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