On July 8, 2026, xAI shipped Grok 4.5, the company's self-described "smartest model" and its first built explicitly for coding and agentic work. Elon Musk pitched it in three words: "Opus-class, but faster." The more interesting part is the price tag — Grok 4.5 arrives at roughly one-third the cost of the frontier models it's chasing, and it does the work in a fraction of the tokens.
Here's the honest read: Grok 4.5 is not the single best coding model on the market. But it may be the best value one, and that's a harder thing for competitors to answer.
What xAI actually built
Grok 4.5 was trained alongside Cursor, using real coding-session data, and reinforcement-learned across tens of thousands of NVIDIA GB300 GPUs. xAI leaned hard into "per-token intelligence" — an asynchronous training stack that let agentic rollouts run for hours while learning continued. The payoff shows up less in peak benchmark scores and more in efficiency.
The headline number: on SWE Bench Pro, Grok 4.5 resolves the average task in 15,954 output tokens versus 67,020 for Anthropic's Opus 4.8 — about 4.2× fewer tokens for comparable results. It's served at 80 tokens per second, fast enough that xAI markets it as quicker than most "flash" tier models.
The benchmarks, without the spin
xAI's own launch charts tell a more nuanced story than the marketing. Grok 4.5 leads on some evals and trails on others:
| Benchmark | Grok 4.5 | Best competitor |
|---|---|---|
| SWE Marathon (resolution) | 29.0% | Opus 4.8 — 26.0% |
| DeepSWE 1.0 (pass@1) | 62.0% | Fable 5 — 66.1% |
| Terminal Bench 2.1 | 83.3% | Fable 5 — 84.3% |
| DeepSWE 1.1 | 53.0% | GPT-5.5 — 67.0% |
| SWE Bench Pro | 64.7% | Fable 5 — 80.4% |
So: Grok 4.5 wins outright on SWE Marathon and stays within a point on Terminal Bench, but it lands behind Fable 5, GPT-5.5, and Opus 4.8 on DeepSWE 1.1 and SWE Bench Pro. On the aggregate Artificial Analysis Intelligence Index, Grok 4.5 scores 54 and ranks fourth — behind Fable 5, GPT-5.5, and Opus 4.8, but ahead of every Gemini and open-weight model.
That's not a knock. Fourth-best frontier intelligence at a budget price is a genuinely strong position.
The price war is the story
This is where Grok 4.5 gets aggressive. Pricing is $2 per million input tokens and $6 per million output tokens, with cached input at $0.50 per million — a 75% discount. xAI claims that undercuts Opus 4.8 and GPT-5.5 by over 60%.
Now stack the token efficiency on top. If Grok 4.5 needs roughly a quarter of the output tokens to finish a coding task and those tokens cost less, the effective cost gap on real agentic workloads widens well beyond the sticker difference. For teams running coding agents at scale — where output tokens dominate the bill — that compounding is the whole pitch.
The competition isn't "which model tops one benchmark." It's "which model finishes the job for the least money." On that axis, Grok 4.5 is hard to beat right now.
What you can actually do with it
Grok 4.5 is the new default in Grok Build, xAI's agentic CLI, and it's available in Cursor on all plans and through the xAI API console as model ID grok-4.5. xAI is offering free usage for a limited time in Grok Build and Cursor.
Beyond code, xAI is pushing Grok 4.5 into office work — building multi-sheet Excel models with web research baked in, assembling PowerPoint decks using native shapes, and drafting Word documents. Whether those features hold up outside curated demos is the kind of thing worth testing before you trust it with a quarterly report.
A calling curl request looks like this:
curl -s https://api.x.ai/v1/responses \
-H "Authorization: Bearer $XAI_API_KEY" \
-H "Content-Type: application/json" \
-d '{"model": "grok-4.5", "input": "Find and fix the bug: function median(a){a.sort();return a[a.length/2]}"}'
The catch
Two things temper the enthusiasm. First, Grok 4.5 isn't available in the EU at launch — not in xAI's products and not in the API console — with availability "expected in mid-July." European teams are locked out for now. Second, the benchmark picture means you shouldn't reach for Grok 4.5 expecting it to beat Fable 5 or Opus 4.8 on the hardest software-engineering suites. It won't. It'll get close, cheaper, and faster.
The Bottom Line
Grok 4.5 reframes the coding-model race around cost-per-completed-task instead of leaderboard bragging rights. It ranks fourth on aggregate intelligence, wins a couple of agentic benchmarks outright, and does it all at roughly a third of the price of Opus 4.8 and GPT-5.5 — while burning far fewer tokens. If you're running coding agents at volume and you're outside the EU, it deserves a spot in your evaluation this week. Just don't expect a benchmark sweep; expect a smaller invoice.
