Argon vs Opus comes down to this: Google's Gemini 4 Argon leads Anthropic's Claude Opus 5.5 on most rows of Google's published benchmark table and on Arena's overall human-preference board, while Opus 5.5 keeps the edge on terminal-style agentic coding. On price they converge. Argon is $2 / $10 per million input/output tokens through November 30, 2026, then $4 / $20 from December 1, the same list price as Opus 5.5.
Gemini 4 Argon vs Opus 5.5 comes down to three things: benchmarks, pricing, and coding. Benchmark figures are vendor-published and labeled by source; Arena and OpenRouter numbers come from AI Rank's dated snapshots. Everything was checked against Google's and Anthropic's official pages on October 15, 2026 (Beijing time). For Argon's full spec sheet and release history, see our Gemini 4 Argon guide.
Gemini 4 Argon vs Opus 5.5 Benchmarks: Google's Table
The numbers below are from Google's Gemini 4 Argon page. They are vendor-reported. Google's methodology note says Argon ran at its highest thinking setting, that competitor figures are mostly the providers' own numbers or public leaderboards, and that some rows (PostTrainBench, LABBench 2, GraphWalks, LVBench) were computed by Google for every model.
| Benchmark | Gemini 4 Argon | Claude Opus 5.5 | Ahead |
|---|---|---|---|
| Vals Index | 68.9% | 67.0% | Argon |
| AutomationBench | 51.3% | 42.5% | Argon |
| Vals Finance Agent v2 | 65.4% | 58.6% | Argon |
| Harvey's Legal Agent Benchmark | 19.6% | 3.8% | Argon |
| PostTrainBench | 45.3% | 49.3% | Opus |
| Terminal-Bench Science 0.1 | 57.6% | 63.3% | Opus |
| LABBench 2 | 88.8% | 73.1% | Argon |
| RiemannBench | 76.0% | 69.6% | Argon |
| GraphWalks up to 128k | 99.7% | 90.6% | Argon |
| GraphWalks 256k–1M | 84.2% | 66.8% | Argon |
| Agent's Last Exam | 39.5% | 38.2% | Argon |
| Chartography | 71.6% | 66.3% | Argon |
| LVBench | 91.7% | 83.7% | Argon |
| CWE-bench v1 | 68.0% | 67.0% | Argon |
Coding rows are in the next section. Across all 18 rows where Google lists both models, Argon is ahead on 14 and Opus 5.5 on 4. Several gaps are small (Agent's Last Exam, CWE-bench, Vals Index), and Google's methodology note says that for Opus 5.5 it used the best available reported reasoning setting when max-effort results were missing. Anthropic notes on its Opus page that Opus 5.5 was evaluated with production safeguards on, which it says likely lowers some cybersecurity and science scores.
Argon vs Opus for Coding
| Coding benchmark (Google table) | Gemini 4 Argon | Claude Opus 5.5 |
|---|---|---|
| DeepSWE v1.1 | 77.9% | 74.2% |
| FrontierSWE v2 | 55.0% | 62.3% |
| Vibe Code Bench | 91.9% | 90.3% |
| Terminal-Bench 4.0 | 57.4% | 66.4% |
Coding is split. Argon leads on DeepSWE v1.1 and Vibe Code Bench; Opus 5.5 leads by 7.3 points on FrontierSWE v2 and 9 points on Terminal-Bench 4.0, where Anthropic reports its result at xhigh effort. Per Google's note, Argon's DeepSWE and Terminal-Bench numbers are self-computed, while the Opus figures come from Anthropic's system card or the public leaderboard.
Arena's coding board, which is human preference rather than a test suite, puts Argon first. In the October 15, 2026 snapshot, gemini-4-argon-high is #1 at 1559.3 (95% interval 1542.2–1576.5, 1,231 votes) and claude-opus-5.5-high is #6 at 1547.5 (1533.6–1561.4, 1,894 votes). The intervals overlap, so this is closer than the rank gap suggests.
→ Coding leaderboard: Arena coding rankings on AI Rank (Arena data published Oct 15, 2026).
Argon vs Opus Pricing
Prices are USD per million tokens, from Google's Gemini API pricing page and Anthropic's Claude API pricing page.
| Item | Gemini 4 Argon, through Nov 30, 2026 | Gemini 4 Argon, from Dec 1, 2026 | Claude Opus 5.5 |
|---|---|---|---|
| Input | $2.00 | $4.00 | $4.00 |
| Output | $10.00 | $20.00 | $20.00 |
| Cached input / cache hit | $0.10 | $0.20 | $0.20 |
| Batch input / output | $1.00 / $5.00 | $2.00 / $10.00 | $2.00 / $10.00 |
A few conditions change the math. Argon's output price includes thinking tokens, it supports implicit caching only, and it is not on the Gemini API free tier. Opus 5.5 charges $5 for a 5-minute cache write and $8 for a 1-hour write, offers a fast mode at $8 / $40, and adds 1.1x for US-only inference. After December 1, the list prices match, so real cost depends on how many tokens each model spends on your tasks.
Specs and Availability
| Gemini 4 Argon | Claude Opus 5.5 | |
|---|---|---|
| API ID | gemini-4-argon |
claude-opus-5-5 |
| Context window | 1,048,576 tokens (input and output combined) | 1M tokens |
| Max output | 65,536 default; up to 1,048,576 with long decode | 128K |
| Reasoning control | Thinking levels low, medium, high | Adaptive thinking, default effort medium |
| Where | Gemini API (Batch, Flex, Priority) | Claude apps (Pro, Max, Team, Enterprise), Claude Platform, AWS, Google Cloud, Microsoft Foundry |
Sources: Google's Argon model page, Anthropic's Opus page and models overview. Anthropic announced Opus 5.5 on September 22, 2026.
Arena and OpenRouter Usage
| Arena, Oct 15, 2026 | Gemini 4 Argon high | Claude Opus 5.5 high |
|---|---|---|
| Overall | #1 · 1523.9 (1515.1–1532.7, 4,904 votes) | #3 · 1508.2 (1500.8–1515.5, 8,300 votes) |
| Coding | #1 · 1559.3 | #6 · 1547.5 |
The overall intervals now overlap by 0.4 points (Argon's lower bound 1515.1, Opus 5.5's upper bound 1515.5); in the October 13 snapshot they had been 0.3 points apart. Neither category separates the two models. Meta's Muse Wonder max is #2 overall between them.
→ Track it on AI Rank: Claude Opus 5.5 — Arena rating, rank and 90-day history
Usage tells a different story because Argon is new. In AI Rank's OpenRouter weekly text ranking for October 10–16, Claude Opus 5.5 is #5 with 5.08T tokens (+34%), while Gemini 4 Argon (google/gemini-4-argon-20261013) is #35 with 377B tokens from its first four days, October 13–16. In the previous week, which counted only its launch day, Argon was #113 with 37.1B.
→ Live usage: See this week's order in the OpenRouter model usage ranking on AI Rank (tokens, Oct 10–16, 2026 window).
Which One to Pick
Through November 30, Argon is half the per-token price, which makes it the cheaper trial for long-context, multimodal, and legal or finance agent work, where Google's table shows its widest margins. For terminal-heavy coding agents, Opus 5.5's Terminal-Bench 4.0 and FrontierSWE v2 numbers make it worth testing side by side. Every benchmark here is vendor-run, so run your own tasks before switching.
Compare before you choose: rankings move as new votes come in — check the current Arena top-rated models on AI Rank before you commit.
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Prepared with automated editorial assistance and checked against official sources and dated AI Rank data on October 15, 2026; Arena, OpenRouter and pricing figures were rechecked on October 22, 2026. We did not run our own benchmarks for this article.