Meta released Llama 4 in April 2025 — its first model family built on a Mixture-of-Experts architecture, with native multimodality and a 10-million-token context window in its Scout variant. The launch was technically ambitious. The reception was complicated. Independent developers panned the real-world quality, a benchmark-manipulation controversy emerged involving Yann LeCun, and by mid-2026 Meta had reorganized its AI division around a new proprietary model line called Muse Spark. This guide covers what Llama 4 actually is, what went wrong, how to run it today, and where Meta’s open-weight strategy stands heading into late 2026.
KEY TAKEAWAYS
Llama 4 is Meta’s fourth generation of open-weight large language models. Unlike its predecessors — which used standard dense transformer architectures — Llama 4 uses a Mixture-of-Experts (MoE) design, meaning only a fraction of the model’s total parameters are active during any given inference step. The family shipped in two publicly released variants:
| Model | Released | Key detail |
|---|---|---|
| Llama 1 | Feb 2023 | Research-only release; weights leaked publicly within days |
| Llama 2 (7B–70B) | July 2023 | First Llama with commercial license; introduced the 700M MAU cap |
| Llama 3 (8B, 70B) | April 2024 | Dense transformer, 8K context, trained on 15T tokens; embedded in WhatsApp/Instagram/Facebook |
| Llama 3.1 (8B, 70B, 405B) | July 2024 | 405B was Meta’s first model pitched as “frontier-level”; 128K context |
| Llama 3.2 / 3.3 | Sept–Dec 2024 | On-device (1B/3B) and vision variants; 3.3 70B matched 3.1 405B on most tasks |
| Llama 4 Scout / Maverick | April 2025 | First MoE Llama; Scout supports 10M-token context on paper; native multimodality via early fusion |
| Llama 4 Behemoth | Not released | Teacher model; still unreleased as of August 2026; Muse Spark may ship first |
| Muse Glimmer (30B) | August 2026 | Apache-licensed open-weight release alongside the proprietary Muse Spark line |
The most significant change from Llama 3 to Llama 4 is not a parameter count — it’s the architecture. Llama 4 Maverick uses a Mixture-of-Experts design: 400 billion total parameters, but only 17 billion activate per token across 128 experts. This keeps inference cost closer to a small dense model while approaching the capability of much larger ones.
Llama 4 also introduced native multimodality through early fusion — text and image tokens are processed together within the same backbone from the start, rather than using a separate frozen vision encoder bolted on afterwards (as in Llama 3.2’s vision variants). This theoretically improves cross-modal reasoning, though real-world results have been mixed.
Enterprise AI vendor Box evaluated Llama 4 against Llama 3 on contract-extraction tasks: both Maverick and Scout reached near-99% accuracy on straightforward fields like party names and dates. On complex clauses such as audit rights, the gap widened sharply — Scout’s accuracy dropped to roughly 45–70%, while Maverick held at 85–92%, making model choice a meaningful decision for legal and compliance workloads rather than a marginal one.
Llama 4 Scout’s 10-million-token context window is the largest of any publicly available open-weight model at launch — roughly 10× Claude 3’s 1-million-token window, at least on paper. In principle, 10 million tokens is enough to feed a model:
The practical caveat is bigger than it first appears. “Needle-in-a-haystack” retrieval performance degrades in the latter portions of very long windows — an issue not unique to Llama 4, but worth testing before committing to an architecture decision that depends on it. In practice, most third-party inference providers initially capped usable context for Scout well below the advertised 10M — typically in the 128K–328K range — due to memory and cost constraints on their infrastructure. Independent long-context evaluations have generally validated strong recall only up to roughly 1M tokens, with retrieval accuracy dropping meaningfully beyond that point. Teams evaluating Scout for genuinely long-context workloads should benchmark on their own documents and chosen provider rather than planning around the 10M headline figure.
Note: the table below reflects the April 2025 launch-era competitive landscape. By August 2026, newer releases such as GPT-5.5 and updated Gemini models have shipped with different context windows, pricing, and benchmark standings — treat this as a historical snapshot of the Llama 4 launch, not a current-state comparison.
| Feature | Llama 4 Scout | Llama 4 Maverick | GPT-4o | Gemini 2.0 Flash |
|---|---|---|---|---|
| Architecture | MoE (17B active / 16 experts) | MoE (17B active / 128 experts) | Dense (undisclosed) | MoE (undisclosed) |
| Context window (advertised) | 10M tokens | 1M tokens | 128K tokens | 1M tokens |
| Multimodal | Text + image (early fusion) | Text + image | Text + image + audio | Text + image + audio |
| Open weights | Yes (with license) | Yes (with license) | Closed | Closed |
| Local deployment | Single H100 | Multi-GPU | API only | API only |
| API cost vs GPT-4o | ~50× cheaper (via cloud APIs) | ~20–30× cheaper | Baseline | ~5× cheaper |
| EU multimodal use | License restricted | License restricted | No restriction | No restriction |
| Fine-tunable | Yes (LoRA / full) | Yes (LoRA / full) | Via OpenAI API | Via Vertex AI |
API cost estimates based on Vellum benchmarking data comparing Llama 3 70B to GPT-4 via cloud providers; Llama 4 Scout costs vary by provider. Check Together.ai, AWS Bedrock, and Cloudflare Workers AI for current pricing.
Meta’s launch material described Llama 4 Maverick as beating GPT-4o and Gemini 2.0 Flash on widely reported benchmarks. The independent developer community was less convinced — and subsequent reporting revealed why.
“The vibes around Llama 4 so far are decidedly mid,” independent AI researcher Simon Willison told Ars Technica shortly after the April 2025 release, pointing to a gap between marketing claims and hands-on developer experience.
Simon Willison
Independent AI researcher, via Ars Technica
The deeper problem emerged later. Meta had submitted a non-release, internally optimized variant of Llama 4 Maverick to the LM Arena chatbot leaderboard — the platform whose crowdsourced rankings many publications cited as evidence of Llama 4’s superiority. The version users could actually download performed substantially worse on the same tasks.
Yann LeCun, Meta’s Chief AI Scientist, departed Meta in November 2025, with his exit effective at year-end 2025, amid the broader reorganization of Meta’s AI division. In an early-January 2026 interview with the Financial Times, LeCun confirmed that Meta had submitted a specially tuned, non-representative version of Llama 4 to the leaderboard — corroborating the gap between the benchmark ranking and real-world performance that developers had already flagged. The episode crystallized existing concerns about benchmark gaming in the AI industry and damaged trust in Meta’s open-model claims among the developer community that Llama depends on for adoption.
The practical consequence was measurable: Groq, a major inference provider, announced it was deprecating Llama 4 Scout 17B due to low developer uptake — a significant signal that the model had not achieved the community traction Meta needed to sustain the open-weight ecosystem flywheel.
Practical implication for teams evaluating Llama 4: benchmark scores from the April 2025 launch should be treated with skepticism. Use independent evals — MMLU, HumanEval, LMSYS — run against the publicly released weights, not leaderboard-specific variants.
On cost and speed, independent benchmarking firm Vellum found that Llama 3 70B could be up to 50 times cheaper and 10 times faster than GPT-4 when accessed via cloud API providers — a gap that remains one of the strongest arguments for open-weight models in production regardless of which generation is used.
Ollama is the simplest way to run Llama 4 Scout locally. You need an NVIDIA H100, A100, or equivalent GPU with at least 40 GB VRAM for the standard variant (quantized versions can run on consumer hardware with less).
# Install Ollama (macOS/Linux) curl -fsSL https://ollama.com/install.sh | sh # Pull and run Llama 4 Scout ollama run llama4 # For a quantized version (lower VRAM, ~24 GB) ollama run llama4:scout-q4_K_M # Run as a local API server ollama serve # Then call via: http://localhost:11434/api/generate
If you don’t want to manage hardware, Llama 4 is available via several cloud providers. Current access points as of August 2026:
| Provider | Model available | Notes |
|---|---|---|
| Together.ai | Scout, Maverick | OpenAI-compatible API; free tier available |
| AWS Bedrock | Scout, Maverick | Fully managed; integrates with IAM/VPC |
| Cloudflare Workers AI | Scout | Serverless, edge-deployed; usage-based billing |
| Meta.ai | Maverick (via chat) | Free consumer access; no API |
| DeepInfra | Scout 17B-16E-Instruct | Low-cost inference API; pay-per-token |
For teams that need domain-specific performance (legal, medical, code), LoRA (Low-Rank Adaptation) is the standard approach for fine-tuning Llama 4 without retraining full weights. Libraries like Hugging Face PEFT, Axolotl, and Unsloth all support Llama 4 Scout fine-tuning. Typical LoRA runs for Scout can be completed on a single 80 GB H100 in a few hours with a modest task-specific dataset.
“Open source” is a loose description of how Llama is actually licensed. In February 2025, the Open Source Initiative (OSI) reviewed the Llama license and concluded it fails on multiple counts: it restricts the freedom to use the software for any purpose, discriminates against users in certain jurisdictions, and restricts fields of endeavor through its Acceptable Use Policy. OSI has publicly accused Meta of promoting Llama as “open source” when it does not meet that bar.
The Llama Community License imposes at least five conditions that no OSI-approved open-source license carries: a monthly-active-user cap, a geographic exclusion, a unilaterally revisable use policy, mandatory branding requirements, and a restriction on using Llama’s own outputs to train competing models.
The specific restrictions enterprises should review before building on Llama 4:
Given these terms, most legal analysts describe Llama as “source-available” or “open-weight” rather than open source. Enterprises evaluating Llama for regulated deployments should also track EU AI Act obligations, which apply based on a model’s risk classification and use case, independent of its licensing terms.
Since mid-2025, Meta has been running two parallel model lines — and understanding the difference matters for teams choosing a foundation model.
| Llama 4 | Muse Spark | |
|---|---|---|
| Weights available | Yes (downloadable) | No (API only) |
| Access model | Download + fine-tune locally | API access only; no weights |
| Primary focus | General-purpose (text + vision) | Coding and developer tooling |
| License | Llama Community License (with restrictions) | Proprietary |
| Trust level post-Llama 4 | Damaged (benchmark controversy) | Too new for independent assessment |
The Muse Spark line — promoted on Meta’s developer platform following the creation of Meta Superintelligence Labs under Alexandr Wang — reflects a strategic shift: Meta is no longer committed to releasing its most capable models as open weights. The community reaction has been split. Many developers welcome continued open releases for some tiers while accepting that frontier-level models may stay proprietary. Others see it as the beginning of a retreat that undermines Llama’s foundational value proposition.
That “retreat” framing is complicated by a more recent data point: in August 2026, Meta released Muse Glimmer, a 30-billion-parameter model under the fully permissive Apache 2.0 license — a genuine OSI-approved open-source release, unlike anything in the Llama Community License lineage. Muse Glimmer doesn’t replace Llama’s role in Meta’s lineup, but it is concrete evidence that Meta is still shipping unrestricted open-weight models even while building out the closed Muse Spark line, supporting a hybrid-strategy reading over a simple retreat narrative.
In April 2026, Axios reported that Meta is developing open-source versions of its next models, reportedly derived from internal projects codenamed Avocado (LLM) and Mango (multimedia generation), while confirming some future models will remain proprietary. Meta’s own framing is that open releases exist alongside proprietary ones, not instead of them — a position that is evolving month by month, and one Muse Glimmer’s release now backs with an actual product rather than just messaging.
For reference, here is what Meta announced at the Llama 3 launch — the basis of this article’s original April 2024 coverage:
Llama models are distributed as open weights, letting developers fine-tune them for specific tasks without per-token licensing costs — a major reason for their fast adoption among startups and enterprises.
Llama 3 was trained on over 15 trillion tokens — seven times the dataset size of Llama 2, with four times more code data.
At launch, Meta reported that human evaluators preferred Llama 3 70B over Llama 2, GPT-3.5, Mistral Medium, and Claude Sonnet (the 2024 model) in blind comparisons. These figures came from Meta’s own evaluation set and were not independently replicated at the time — a pattern that would repeat with Llama 4.
Meta has a track record of adapting ideas — Stories from Snapchat, Reels from TikTok — into products that succeed at scale. Llama followed a similar pattern: Meta arrived late to foundation models but embedded them directly into WhatsApp, Instagram, and Facebook, reaching an install base no standalone AI product can match. Llama 3 was the first model integrated into Meta.ai as a public assistant — a direct ChatGPT challenger reaching over 3 billion combined users.
Read More
For a broader look at open-weight models beyond Llama, see our guide to open-source LLMs. If you’re evaluating Databricks or Databricks-hosted Llama deployments, see The Databricks Phenomenon.
References
Yes, in several ways. You can access Llama 4 Maverick for free via Meta.ai (the consumer chat interface). You can download the model weights for free from Meta’s website or Hugging Face and run them on your own hardware. Cloud API providers like Together.ai offer free-tier access for low-volume usage. The commercial license is also free for most businesses — the 700M MAU cap only affects a handful of the largest global platforms.
The April 2025 launch was controversial on two fronts. First, real-world developer feedback was consistently below the benchmark claims — summarized bluntly by Simon Willison as “decidedly mid.” Second, it emerged that Meta had submitted a non-release, optimized variant of Maverick to the LM Arena leaderboard rather than the publicly available weights, inflating the model’s apparent ranking. Yann LeCun, who left Meta at the end of 2025, confirmed the manipulation in a Financial Times interview in early January 2026. Combined with Groq’s subsequent decision to deprecate Llama 4 Scout 17B due to low adoption, the launch is widely considered a setback for Meta’s open-model credibility.
Llama 4 Scout is best suited for long-context tasks — processing entire codebases, large document sets, or long-form transcripts — and for teams that need to run a capable model on a single GPU, keeping in mind that usable context in production has generally proven narrower than the advertised 10M tokens. Llama 4 Maverick is better for reasoning-intensive tasks, coding, and multimodal use cases where you have multi-GPU or cloud infrastructure. Both are suitable for fine-tuning on domain-specific tasks via LoRA without full retraining.
Llama 3 uses a dense transformer architecture with an 8K–128K context window (depending on variant). Llama 4 introduced Mixture-of-Experts architecture, native multimodality via early fusion, and — in Scout — an advertised context window of up to 10 million tokens. Llama 4 Maverick has significantly more total parameters (400B) but similar active-parameter costs to Llama 3 70B during inference.
On benchmarks as reported by Meta at launch, Llama 4 Maverick was claimed to match or beat GPT-4o — though those figures came from a non-release variant and should be treated cautiously. In independent evaluations, GPT-4o generally performs better on complex reasoning and instruction-following tasks. However, Llama 4 Scout is far cheaper (up to ~50× vs GPT-4 per token via cloud APIs) and uniquely offers local deployment — advantages GPT-4o cannot match. The better choice depends on your workload and infrastructure constraints, not a single benchmark number. Note also that both GPT-4o and Gemini 2.0 Flash have since been superseded by newer releases as of August 2026, so this comparison reflects the April 2025 landscape.
No, strictly speaking. Llama models are “open weight”: the trained model files are downloadable and can be fine-tuned and deployed commercially, but the Llama 4 Community License includes a 700M monthly-active-user cap, an EU exclusion for multimodal capabilities, output-training restrictions, and a unilaterally revisable Acceptable Use Policy — conditions the Open Source Initiative explicitly excludes from its Open Source Definition. Meta’s August 2026 release of Muse Glimmer under a genuine Apache 2.0 license shows the company can and does ship true open-source models — just not, so far, under the Llama name.
As of August 2026, Behemoth has not been publicly released. Meta has described it primarily as a “teacher model” used to improve Scout and Maverick through codistillation. Community speculation, driven by active discussion in r/LocalLLaMA and on X, suggests further Muse-branded models may ship before Behemoth — though Meta has not confirmed a timeline for either.
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