Exaone 4.0 1.2B (Reasoning)

An intelligent, open-weight model from LG AI Research.

Exaone 4.0 1.2B (Reasoning)

A highly capable and verbose open-weight model from LG AI Research, offering top-tier intelligence for its size class at an exceptionally competitive price point.

LG AI Research1.2B Parameters64k ContextOpen LicenseHigh IntelligenceText Generation

Exaone 4.0 1.2B (Reasoning) is a small-yet-mighty language model developed by LG AI Research. As part of the broader Exaone family, this model represents a significant effort to pack advanced capabilities into a compact, efficient, and accessible package. The "Reasoning" variant is specifically tuned for tasks that require logical deduction, problem-solving, and multi-step thinking, setting it apart from more generalized text generation models. Despite its relatively small parameter count of 1.2 billion, it punches well above its weight, demonstrating that thoughtful architecture and high-quality training data can rival the performance of much larger models in specific domains.

In our standardized testing, Exaone 4.0 1.2B achieves an impressive score of 27 on the Artificial Analysis Intelligence Index. This places it at rank #4 out of 30 comparable models, a remarkable feat that positions it firmly in the top tier. The class average for intelligence is just 14, meaning Exaone more than doubles the typical performance. This high score indicates a strong aptitude for understanding complex prompts, following instructions, and generating coherent, logically sound responses. It suggests that for developers needing a reliable reasoning engine without the overhead of a 70B+ parameter model, Exaone is a formidable contender.

One of the most striking features of this model is its pricing structure. With an API cost of $0.00 per million input tokens and $0.00 per million output tokens, it is, by our metrics, the most affordable model in its class. This pricing suggests that the model is intended for free use via self-hosting or through specific research and partnership programs by LG. This effectively removes the per-token cost barrier, making it an incredibly attractive option for startups, researchers, and developers on a tight budget. The primary cost consideration shifts from API calls to the operational expenses of hosting and inference, a trade-off many are willing to make for this level of performance.

However, this cost-effectiveness comes with a notable characteristic: high verbosity. During our intelligence evaluation, the model generated 71 million tokens, a figure that dwarfs the class average of 10 million. This means Exaone tends to provide extremely detailed, comprehensive, and sometimes loquacious answers. While this can be a significant advantage for tasks like report generation or detailed explanations, it can also be a drawback for applications requiring concise, to-the-point responses. This verbosity, combined with a generous 64,000-token context window, makes the model well-suited for deep analysis of long documents but requires careful prompt engineering to control output length for other use cases.

Scoreboard

Intelligence

27 (4 / 30)

Scores significantly above the class average of 14, placing it in the top tier for reasoning capabilities among its peers.
Output speed

N/A tokens/sec

Performance data for output speed is not currently available. Real-world throughput will depend on the hosting environment.
Input price

0.00 USD per 1M tokens

Ranked #1 for affordability, this model's free input pricing makes it exceptionally cost-effective.
Output price

0.00 USD per 1M tokens

Also ranked #1, the free output pricing solidifies its position as a top choice for budget-conscious projects.
Verbosity signal

71M tokens

Extremely verbose, generating over 7 times the average token count (10M) in our intelligence benchmark tests.
Provider latency

N/A seconds

Time-to-first-token data is not available. Latency will be determined by the specific inference setup and hardware.

Technical specifications

Spec Details
Model Name Exaone 4.0 1.2B
Variant Reasoning
Owner LG AI Research
License Open (Specifics of the license should be verified from the source)
Parameters ~1.2 Billion
Context Window 64,000 tokens
Input Modalities Text
Output Modalities Text
Architecture Transformer-based Decoder-only
Primary Language English (with multilingual capabilities)
Release Date Unspecified in provided data
Intended Use Reasoning, Q&A, Summarization, Text Generation

What stands out beyond the scoreboard

Where this model wins
  • Exceptional Intelligence: For a 1.2B parameter model, its score of 27 on the Intelligence Index is outstanding, making it a top choice for tasks requiring logical reasoning and problem-solving.
  • Unbeatable Price: With a listed price of $0.00 for both input and output, the model is essentially free to use, with costs shifting entirely to compute and hosting. This dramatically lowers the barrier to entry for sophisticated AI applications.
  • Large Context Window: A 64k context window is very generous for a model of this size, enabling it to process and analyze long documents, extensive chat histories, or large codebases in a single pass.
  • Open and Accessible: As an open-weight model, it offers flexibility for fine-tuning, research, and deployment in private environments, giving developers full control over their AI stack.
  • Comprehensive Outputs: Its high verbosity can be a major asset for use cases where detail and thoroughness are paramount, such as generating detailed reports, educational materials, or in-depth explanations.
Where costs sneak up
  • High Verbosity: The model's tendency to generate a high volume of tokens can be a double-edged sword. While the tokens themselves are free, they require more compute time for generation, potentially leading to slower response times and higher infrastructure costs.
  • Self-Hosting Overhead: The $0.00 price tag implies self-hosting. This introduces costs for infrastructure (e.g., GPUs, servers), maintenance, and the engineering expertise required to deploy and scale the model effectively.
  • Unknown Performance Metrics: The lack of public data on speed (tokens/sec) and latency (time-to-first-token) makes it difficult to predict real-world performance. Production applications may face unexpected bottlenecks.
  • Prompt Engineering Demands: To manage its high verbosity and get concise answers when needed, users will need to invest time in sophisticated prompt engineering and potentially implement output parsing logic.
  • Smaller Model Limitations: While highly intelligent for its size, a 1.2B model may lack the nuance, world knowledge, and resistance to hallucination of state-of-the-art models with 70B+ parameters, especially for highly complex or creative tasks.

Provider pick

As an open-weight model with a listed price of $0.00, Exaone 4.0 1.2B is not typically offered through traditional pay-as-you-go API providers. Instead, "providers" are the platforms and methods you use to host the model yourself. The best choice depends on your team's technical expertise, budget for infrastructure, and scalability requirements.

Priority Pick Why Tradeoff to accept
Cost-Effectiveness On-Premise Server If you already own suitable hardware (especially GPUs), this is the cheapest long-term option as you only pay for power and maintenance. Requires significant upfront capital investment if you don't own hardware, plus dedicated expertise for setup and maintenance.
Balanced Choice Cloud VM (e.g., AWS, GCP, Azure) Offers a balance of control and flexibility. You can choose the exact GPU instance (like an A10G or T4) that fits your performance and budget needs, and scale up or down as required. Can be complex to configure and manage. Costs can become unpredictable if usage spikes, and you are responsible for all software setup.
Ease of Use Managed Inference Service (e.g., Hugging Face, Replicate) These platforms handle all the infrastructure complexity. You can often deploy a model like Exaone with a few clicks, providing an API endpoint automatically. This is the most expensive hosting option, as you pay a premium for the convenience. You also have less control over the underlying hardware.
Scalability Kubernetes on Cloud For high-demand production applications, deploying the model on a Kubernetes cluster provides maximum scalability, resilience, and automated management. This is the most complex and engineering-intensive approach, requiring deep expertise in both MLOps and cloud-native infrastructure.

Note: The choice of hosting will directly impact the model's real-world latency and throughput. Performance benchmarks are recommended on your target infrastructure before committing to a production deployment.

Real workloads cost table

To understand how Exaone 4.0 1.2B performs in practice, let's examine several real-world scenarios. These examples highlight how its intelligence, large context window, and high verbosity play out. The estimated cost for all scenarios is $0.00 in API fees, but remember to factor in your own compute and hosting costs.

Scenario Input Output What it represents Estimated cost
Document Analysis & Summary A 15-page PDF research paper (~7,500 words, ~10k tokens) is provided as input. The model produces a detailed 3-page summary (~1,500 words, ~2k tokens) covering methodology, findings, and limitations. Demonstrates the 64k context window's ability to handle long documents and the model's capacity for detailed, structured output. $0.00
Code Explanation A 300-line Python script (~1.5k tokens) with complex logic is provided. The model generates a line-by-line explanation with examples, totaling over 800 words (~1.1k tokens). Highlights the model's reasoning capabilities applied to code, and its tendency towards high verbosity and detail. $0.00
Customer Support Email Triage An angry customer email (~300 tokens) is input with a request to classify intent and draft a reply. The model correctly identifies the issue and drafts a very polite, thorough, and empathetic response of 400 words (~550 tokens). Shows its utility in customer-facing roles, but the verbose output might need to be manually shortened by an agent. $0.00
Brainstorming Session A simple prompt: "Brainstorm five unique marketing angles for a new eco-friendly water bottle." (~20 tokens). The model provides five distinct angles, each with a detailed paragraph explaining the target audience, messaging, and potential channels (~700 tokens). A great example of its creative and reasoning abilities, where verbosity is a clear advantage for generating rich ideas. $0.00

Exaone 4.0 1.2B excels at tasks where detail and thoroughness are valued. Its large context window is a key asset for document-heavy workloads. However, for applications needing quick, concise answers, its high verbosity requires active management through careful prompting or post-processing to avoid overly long outputs.

How to control cost (a practical playbook)

While Exaone 4.0 1.2B is nominally "free" at the API level, real-world costs are driven by the compute infrastructure required to run it. Managing these operational costs is key to leveraging the model effectively. The primary goals are to optimize hardware utilization and control the model's verbose nature to reduce generation time.

Control Verbosity with Prompt Engineering

The most direct way to manage compute time is to manage output length. Since Exaone is naturally verbose, your prompts must be explicit about the desired output format and length.

  • Set explicit constraints: Add phrases like "Answer in a single sentence," "Provide a three-bullet-point summary," or "Be concise."
  • Use structured formats: Request output in JSON or a specific schema. This forces the model to conform to a structure and often reduces conversational filler.
  • Few-shot prompting: Provide examples in your prompt that demonstrate the desired level of brevity. The model will learn from the examples and adjust its output accordingly.
Optimize Your Hosting Infrastructure

Choosing the right hardware and software stack is critical for cost-effective inference. A misconfigured environment can lead to wasted resources and high bills.

  • Right-size your GPU: A 1.2B model does not require a top-of-the-line A100 or H100 GPU. A more modest GPU like an NVIDIA T4 or A10G can often provide sufficient performance at a fraction of the cost.
  • Use quantization: Convert the model weights from 16-bit floating point (FP16) to 8-bit or 4-bit integers (INT8/INT4). This reduces the model's memory footprint and can significantly speed up inference with minimal impact on accuracy.
  • Leverage optimized runtimes: Use inference servers like TensorRT-LLM or vLLM, which are specifically designed for high-throughput, low-latency transformer inference.
Implement Caching and Request Batching

Reduce redundant computations by intelligently managing how you process requests. This is especially important for applications with repetitive queries.

  • Cache common requests: If your users frequently ask the same questions, store the model's response in a fast cache (like Redis). Serve the cached response instead of running the model again, saving significant compute.
  • Batch incoming requests: Instead of processing each request individually, group them into batches to be processed by the GPU simultaneously. This dramatically improves hardware utilization and overall throughput, reducing the per-request cost.

FAQ

What is Exaone 4.0 1.2B (Reasoning)?

Exaone 4.0 1.2B (Reasoning) is an open-weight language model with approximately 1.2 billion parameters, developed by LG AI Research. This specific variant has been fine-tuned to excel at tasks requiring logical deduction, problem-solving, and multi-step thinking.

How does it compare to other models in its size class?

It performs exceptionally well. In our testing, it scored 27 on the Artificial Analysis Intelligence Index, placing it #4 out of 30 comparable models and well above the class average of 14. This suggests it is one of the most capable reasoning models at this parameter scale.

Is the model truly free to use?

The model weights are released under an open license, and benchmarked API providers list the price as $0.00. This means there are no per-token fees to use the model's logic. However, you are responsible for the costs of hosting it, which includes server infrastructure (preferably with a GPU), electricity, and maintenance. So, while the software is free, running it is not.

What does its "high verbosity" mean in practice?

It means the model tends to generate very long, detailed, and comprehensive answers by default. In our tests, it produced over seven times more text than the average model. This can be an advantage for tasks like report generation but may require careful prompt engineering to get concise answers for other applications, like chatbots or quick data extraction.

What are the ideal use cases for this model?

Given its strengths, Exaone 4.0 1.2B is ideal for:

  • Complex Q&A: Answering questions that require analyzing information from long documents.
  • Content Generation: Writing detailed articles, reports, or educational materials.
  • Code Analysis: Explaining or documenting complex code snippets.
  • Brainstorming: Generating a wide range of detailed ideas from a simple prompt.
How large is the 64k context window and why does it matter?

A 64,000-token context window is very large, equivalent to roughly 48,000 words or about 100 single-spaced pages of text. This is a significant advantage because it allows the model to process and 'remember' vast amounts of information in a single prompt, making it perfect for summarizing long reports, analyzing entire codebases, or maintaining long, coherent conversations without losing track of earlier details.


Subscribe