Grok 4.5 Review 2026: xAI's Fastest, Most Agentic Model Yet

Grok 4.5, launched July 8, 2026, is xAI's most useful model to date — not because it tops the raw intelligence charts (it lands #4), but because it's the most token-efficient agent on the board. It resolves engineering tasks in roughly a quarter of the output tokens that a flagship like Opus 4.8 uses, which translates directly into lower bills and faster runs. For anyone building agents or coding with an LLM in the loop, that efficiency is the story. Here's the honest read.

What's new in Grok 4.5

Grok 4.5 shipped through Grok Build, Cursor, and the xAI API. It's a multimodal model that accepts both text and image input — screenshots, diagrams, charts, scanned documents — and lets you dial reasoning effort to low, medium, or high, with high as the default. That control matters: you spend more tokens only when a problem needs the deeper thinking.

The headline design goal was efficiency, not just raw scores. xAI tuned 4.5 to reach answers with less wasted reasoning, and it shows in both cost and latency. The documented knowledge cutoff is February 1, 2026, so it's current on recent developments.

Benchmarks

On Artificial Analysis's Intelligence Index, Grok 4.5 lands #4 of 168 models with a score of 54 — a strong result, if not the outright leader. Where it genuinely tops the board is agentic tool use: it posts the single best agentic tool-use result of any model tested, which is exactly the capability that matters for real automation.

So read the numbers correctly. If you want the absolute highest reasoning ceiling on hard one-shot problems, models like GPT-5.6 and Claude sit above it. If you want a model that reliably drives tools, calls functions, and completes multi-step tasks, Grok 4.5 is at the top.

Agentic & coding

This is Grok 4.5's home turf. xAI reports it resolving engineering tasks in an average of 15,954 output tokens against roughly 67,020 for a max-effort Opus 4.8 run — about 4.2× fewer tokens for comparable results. In agent loops that call the model dozens of times, that compounds into dramatically lower cost and faster completion.

The 500K-token context is big enough for large repositories, research packets, long transcripts, and multi-file projects. Paired with the best-in-class tool use, it makes Grok 4.5 a genuinely good coding and automation engine inside tools like Cursor. The one regression: that 500K window is smaller than the 1M context on the earlier Grok 4.3, so a handful of extreme long-context jobs are actually better served by the previous model.

Pricing

Grok 4.5 is priced aggressively on the API, and the token efficiency makes the effective cost even lower than the sticker rate suggests.

Access	Price	Notes
API input	$2 / M tokens	Cached input heavily discounted (~$0.30-$0.50/M)
API output	$6 / M tokens	500K context; no batch discount published
SuperGrok Lite	$10/mo	Entry consumer tier, Grok Imagine, one agent
SuperGrok	$30/mo	Full Grok access, $300/yr annual (~17% off)
SuperGrok Heavy	$300/mo	Multi-agent tier, first to get full 4.5 access

Because 4.5 needs ~4× fewer output tokens on agentic work, its real-world cost per completed task often undercuts pricier-looking models. Developers can also draw up to $175/mo in free API credits through xAI's data-sharing program. For the full plan-by-plan picture, see our Grok 4.5 pricing guide.

Pros & cons

Who it's for

Use Grok 4.5 if you build agents, run coding workflows, or care about per-task cost — its token efficiency and tool use make it the value pick for automation in 2026. Look elsewhere if you need the absolute highest reasoning on hard problems (GPT-5.6 or Claude) or the largest possible context, where even the older Grok 4.3's 1M window wins.

Comparing flagships? Read Grok 4.5 vs GPT-5.6, our original Grok review, or where it lands in the best AI chatbots roundup.