GPT-5.3-Codex vs Llama 4 Maverick

OpenAI · US  |  Meta · US · Updated June 2026

Quick verdict

Pick GPT-5.3-Codex for dedicated coding agent or cli and ide integration. Pick Llama 4 Maverick for open weights, 1m context or strong image + text understanding. Choose Llama 4 Maverick if you need self-hosting or data privacy; GPT-5.3-Codex if you want a managed API.

GPT-5.3-Codex (OpenAI) and Llama 4 Maverick (Meta) are two of the models people most often weigh against each other in 2026. GPT-5.3-Codex is openAI's coding-specialized agent model for autonomous software engineering. Llama 4 Maverick is meta's open-weight 1M-context multimodal model for self-hosted deployments. They diverge most on price, context window and open vs. closed weights — each quantified below from the models' real specs.

Key differences at a glance

Side-by-side specs

SpecGPT-5.3-CodexLlama 4 Maverick
ProviderOpenAI (US) Meta (US)
ReleasedFebruary 24, 2026 April 2025
Context window400K (~600 pages) 1M (~1,500 pages)
Price (in/out)$1.75/$14 per 1M tokens Open weight (self-host / free)
Open weight?No — API only Yes — self-hostable
Modalitiestext, code text, image, code
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Dedicated coding agent

GPT-5.3-Codex

OpenAI's coding-specialized agent model for autonomous software engineering — and it is the newer of the two.

CLI and IDE integration

GPT-5.3-Codex

GPT-5.3-Codex lists cLI and IDE integration among its strengths; Llama 4 Maverick does not.

Autonomous software tasks

GPT-5.3-Codex

GPT-5.3-Codex lists autonomous software tasks among its strengths; Llama 4 Maverick does not.

Open weights, 1M context

Llama 4 Maverick

Its 1M window holds about 2.5× more than GPT-5.3-Codex's 400K in a single prompt.

Strong image + text understanding

Llama 4 Maverick

Meta's open-weight 1M-context multimodal model for self-hosted deployments — and it carries the larger 1M context.

Self-hostable

Llama 4 Maverick

Open weights make this possible at all — GPT-5.3-Codex is API-only, so it cannot leave the vendor's servers.

Lowest cost at scale

Llama 4 Maverick

Its weights are open, so at volume you pay for your own hardware instead of GPT-5.3-Codex's $1.75/$14 per 1M tokens.

Largest single-prompt input

Llama 4 Maverick

Its 1M window is about 2.5× larger than GPT-5.3-Codex's 400K, fitting roughly 1,500 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

Llama 4 Maverick

At Open weight (self-host / free) it undercuts GPT-5.3-Codex, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

Llama 4 Maverick

Larger 1M window fits more in one prompt.

A team with data-privacy or self-hosting needs

Llama 4 Maverick

Open weights let you run it on your own hardware; GPT-5.3-Codex is API-only.

Anyone whose priority is dedicated coding agent

GPT-5.3-Codex

It is specifically built for that.

Anyone whose priority is open weights, 1m context

Llama 4 Maverick

That is its strongest area.

GPT-5.3-Codex: where it fits

OpenAI's coding-specialized agent model for autonomous software engineering. Released February 24, 2026 by OpenAI, it is built for dedicated coding agent, cLI and IDE integration, autonomous software tasks, and tool calling.

Its trade-offs are real: coding-specialized, narrower general use, and retired in favor of GPT-5.5 Codex. At $1.75 in / $14 out per million tokens, it sits in the mid price band.

Llama 4 Maverick: where it fits

Meta's open-weight 1M-context multimodal model for self-hosted deployments. Released April 2025 by Meta, it is built for open weights, 1M context, strong image + text understanding, self-hostable, and 400B MoE, 17B active.

Its trade-offs: needs serious hardware to self-host, and trails closed frontier on reasoning. As an open-weight model, its running cost is your own hardware rather than a per-token fee.

The bottom line for this matchup

The defining split here is open vs. closed. Llama 4 Maverick gives you weights you control — self-host it, fine-tune it, keep data in-house, pay only for hardware. GPT-5.3-Codex gives you a managed, always-updated API with no infrastructure to run. Teams with GPUs, privacy requirements, or huge volume often favour the open model; teams that want zero ops and the latest capabilities favour the closed one. Capability is close enough that this operational question, not the benchmark, usually decides it.

Want both GPT-5.3-Codex and Llama 4 Maverick without two subscriptions? LumiChats gives you these plus 40+ models under one ₹69/day pass (about $1/day) — draft with one, cross-check with the other.

See pricing

Frequently asked questions

Is GPT-5.3-Codex or Llama 4 Maverick better for coding?

Public SWE-Bench figures are not available for either model, so the honest test is your own repository — run an identical real bug through both. By design, GPT-5.3-Codex leans toward dedicated coding agent while Llama 4 Maverick leans toward open weights, 1m context, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, GPT-5.3-Codex or Llama 4 Maverick?

Llama 4 Maverick is open-weight, so self-hosting means no per-token fee (you pay for hardware instead), while GPT-5.3-Codex is API-metered at $1.75/$14 per 1M tokens. For most teams without GPUs, the API model is cheaper to start; at very high volume, self-hosting can win.

Which has the bigger context window?

Llama 4 Maverick — 1M vs 400K, about 2.5× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both GPT-5.3-Codex and Llama 4 Maverick together?

Yes — a multi-model platform like LumiChats gives you GPT-5.3-Codex, Llama 4 Maverick and 40+ others under one ₹69/day pass (about $1/day), so you can draft with one and cross-check with the other instead of buying two subscriptions.

Which is newer, GPT-5.3-Codex or Llama 4 Maverick?

GPT-5.3-Codex — released February 24, 2026, about 11 months after Llama 4 Maverick.

Related comparisons

Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.