GPT-5.4 Nano vs Grok 4.5

OpenAI · US  |  xAI · US · Updated June 2026

Quick verdict

Pick GPT-5.4 Nano for cheapest gpt-5.4-family tier at $0.20/$1.25 — built for high-volume, latency-sensitive work or classification, extraction, ranking and sub-agent execution at scale. Pick Grok 4.5 for cheap, token-efficient agentic coding — about gpt-5.5-codex quality at roughly half the cost or extreme token efficiency — around 4x fewer output tokens per task than opus 4.8. On a tight budget at scale, GPT-5.4 Nano is the value pick.

GPT-5.4 Nano (OpenAI) and Grok 4.5 (xAI) are two of the models people most often weigh against each other in 2026. GPT-5.4 Nano is openAI's cheapest GPT-5.4 variant at $0.20/$1.25 with a 400K window — a speed-and-cost tier for high-volume tasks, not deep reasoning. Grok 4.5 is xAI's first coding-focused model — pitched as Opus-class but faster, more token-efficient, and cheaper, undercutting GPT-5.5-Codex. They diverge most on price and context window — each quantified below from the models' real specs.

Key differences at a glance

Side-by-side specs

SpecGPT-5.4 NanoGrok 4.5
ProviderOpenAI (US) xAI (US)
ReleasedMarch 17, 2026 July 8, 2026
Context window400K (~600 pages) 500K (~750 pages)
Price (in/out)$0.2/$1.25 per 1M tokens $2/$6 per 1M tokens
Open weight?No — API only No — API only
Modalitiestext, image, code text, image, code
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Cheapest GPT-5.4-family tier at $0.20/$1.25 — built for high-volume, latency-sensitive work

GPT-5.4 Nano

At $0.2/$1.25 per 1M tokens it undercuts Grok 4.5 ($2/$6 per 1M tokens), and that gap compounds at volume.

Classification, extraction, ranking and sub-agent execution at scale

GPT-5.4 Nano

OpenAI's cheapest GPT-5.4 variant at $0.20/$1.25 with a 400K window — a speed-and-cost tier for high-volume tasks, not deep reasoning — and it runs cheaper at $0.2/$1.25 per 1M tokens.

A 400K context in the smallest, fastest GPT-5.4 variant

GPT-5.4 Nano

Grok 4.5 is comparatively weak here — smaller 500K context (halved from the 1M generation), with pricing that doubles above 200K tokens

Cheap, token-efficient agentic coding — about GPT-5.5-Codex quality at roughly half the cost

Grok 4.5

Its 500K window holds about 1.3× more than GPT-5.4 Nano's 400K in a single prompt.

Extreme token efficiency — around 4x fewer output tokens per task than Opus 4.8

Grok 4.5

XAI's first coding-focused model — pitched as Opus-class but faster, more token-efficient, and cheaper, undercutting GPT-5.5-Codex — and it carries the larger 500K context.

In-IDE coding, trained on real Cursor developer sessions and shipped natively in Cursor

Grok 4.5

GPT-5.4 Nano is comparatively weak here — a nano tier — not built for hard reasoning or frontier coding

Lowest cost at scale

GPT-5.4 Nano

At $0.2/$1.25 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Largest single-prompt input

Grok 4.5

Its 500K window is about 1.3× larger than GPT-5.4 Nano's 400K, fitting roughly 750 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

GPT-5.4 Nano

At $0.2/$1.25 per 1M tokens it undercuts Grok 4.5, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

Grok 4.5

Larger 500K window fits more in one prompt.

Anyone whose priority is cheapest gpt-5.4-family tier at $0.20/$1.25 — built for high-volume, latency-sensitive work

GPT-5.4 Nano

It is specifically built for that.

Anyone whose priority is cheap, token-efficient agentic coding — about gpt-5.5-codex quality at roughly half the cost

Grok 4.5

That is its strongest area.

GPT-5.4 Nano: where it fits

OpenAI's cheapest GPT-5.4 variant at $0.20/$1.25 with a 400K window — a speed-and-cost tier for high-volume tasks, not deep reasoning. Released March 17, 2026 by OpenAI, it is built for cheapest GPT-5.4-family tier at $0.20/$1.25 — built for high-volume, latency-sensitive work, classification, extraction, ranking and sub-agent execution at scale, a 400K context in the smallest, fastest GPT-5.4 variant, and text and image input for cheap multimodal pipelines.

Its trade-offs are real: a nano tier — not built for hard reasoning or frontier coding, no published SWE-Bench Verified score (OpenAI reported SWE-Bench Pro instead), outclassed by GPT-5.4 and GPT-5.4 Mini whenever a task needs real depth, and image input only — no audio or video. At $0.2 in / $1.25 out per million tokens, it sits in the budget price band.

Grok 4.5: where it fits

XAI's first coding-focused model — pitched as Opus-class but faster, more token-efficient, and cheaper, undercutting GPT-5.5-Codex. Released July 8, 2026 by xAI, it is built for cheap, token-efficient agentic coding — about GPT-5.5-Codex quality at roughly half the cost, extreme token efficiency — around 4x fewer output tokens per task than Opus 4.8, in-IDE coding, trained on real Cursor developer sessions and shipped natively in Cursor, and top-tier placement on the Artificial Analysis Intelligence Index.

Its trade-offs: smaller 500K context (halved from the 1M generation), with pricing that doubles above 200K tokens, and eU launch delayed; no open weights. At $2 in / $6 out per million tokens, it sits in the mid price band.

The bottom line for this matchup

GPT-5.4 Nano and Grok 4.5 overlap enough that the right pick depends on your specific job. GPT-5.4 Nano costs less per token; Grok 4.5 holds the larger context; and each leads in its own area — GPT-5.4 Nano for cheapest gpt-5.4-family tier at $0.20/$1.25 — built for high-volume, latency-sensitive work, Grok 4.5 for cheap, token-efficient agentic coding — about gpt-5.5-codex quality at roughly half the cost. Rather than crowning one, run the same hard task through both once and let the results decide.

Want both GPT-5.4 Nano and Grok 4.5 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-5.4 Nano or Grok 4.5 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-5.4 Nano leans toward cheapest gpt-5.4-family tier at $0.20/$1.25 — built for high-volume, latency-sensitive work while Grok 4.5 leans toward cheap, token-efficient agentic coding — about gpt-5.5-codex quality at roughly half the cost, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, GPT-5.4 Nano or Grok 4.5?

GPT-5.4 Nano is cheaper — $0.2/$1.25 per 1M tokens vs $2/$6 per 1M tokens, roughly 10× apart on input.

Which has the bigger context window?

Grok 4.5 — 500K vs 400K, about 1.3× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both GPT-5.4 Nano and Grok 4.5 together?

Yes — a multi-model platform like LumiChats gives you GPT-5.4 Nano, Grok 4.5 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-5.4 Nano or Grok 4.5?

Grok 4.5 — released July 8, 2026, about 4 months after GPT-5.4 Nano.

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.