Gemini 4 Argon Thinking Levels Tested: Is “High” Worth the Wait? A hands-on test of Google's Gemini 4 Argon (API model ID gemini-4-argon), launched for developers on October 13, 2026, found that the Medium thinking level produced the best balance when all three levels were asked to build the same single-file tower defense game: Medium finished fastest at 3:10 with 1,739 lines and 29/30 on the 30-point checklist, Low took 3:50 with 2,095 lines and a perfect 30/30, and High took 6:09 with 2,413 lines and 29/30. High's extra time yielded a more polished interface and 504 enemies per full game versus 352 for Medium and 348 for Low, but no fewer bugs, with Medium losing a point for hiding the score behind a button and High for hiding the start button on phones. Google's developer docs list medium as the default thinking_level and recommend testing all three levels and using the lowest that meets a quality bar. Results card: Gemini 4 Argon Low took 3:50, wrote 2,095 lines, scored 30/30 and sent 348 enemies; Medium took 3:10, wrote 1,739 lines, scored 29/30 and sent 352 enemies; High took 6:09, wrote 2,413 lines, scored 29/30 and sent 504 enemies Quick answer: In our test, Medium was the best pick . We gave Gemini 4 Argon the same prompt for a full tower defense game at Low, Medium and High thinking. All three games worked. Low passed all 30 checks, and Medium and High passed 29 each, with one small flaw apiece. Medium finished fastest 3:10 , Low took 3:50, and High took 6:09 , almost twice as long. High’s extra time bought a more polished interface and about 150 more enemies per game. It did not buy fewer bugs. Use Medium for most coding, and switch to High when you want a bigger, more polished result and can wait. | | Low | Medium | High | |---|---|---|---| | Time to generate | 3:50 | 3:10 | 6:09 | | Code length | 2,095 lines | 1,739 lines | 2,413 lines | | Our 30-point checklist | 30/30 | 29/30 | 29/30 | | Lost a point for | – | Score hidden behind a button | Start button hidden on phones | | Beat all 10 waves test bot | Yes | Yes | Yes | | Enemies in one full game | 348 | 352 | 504 | | Console errors | 0 | 0 | 0 | | Best for | Nothing over Medium here | Most coding tasks | Polish and extra content | You can play all three games https://docs.google.com/document/d/1lJtv6vb7nXJlCWWKrttv4km-kakOBHCAW1-1vipwczM/edit bookmark=id.f6jf4xkjt3y and download our raw data https://docs.google.com/document/d/1lJtv6vb7nXJlCWWKrttv4km-kakOBHCAW1-1vipwczM/edit bookmark=id.hcnawxms977h further down this page. What are Gemini 4 Argon’s thinking levels? Gemini 4 Argon API model ID gemini-4-argon is Google’s newest frontier model. It launched for developers on October 13, 2026 and is rolling out to Google AI Pro and Ultra subscribers in the Gemini app. Like other “thinking” models, it reasons before it answers. You choose how much it reasons: - Low: “Quick and efficient” the Gemini app’s own label - Medium: “Balanced depth” - High: “Extra thorough” In the Gemini app, you pick Argon from the model menu, then open Thinking level . Gemini app model menu with 4 Argon selected and the Thinking level submenu open, showing Low Quick and efficient , Medium Balanced depth and High Extra thorough The Gemini app’s model menu during our test. 4 Argon and the three thinking levels are boxed in red. On the API, the same setting is called thinking level, with the values low, medium and high. Google’s developer docs say medium is the default , and they recommend testing all three and using the lowest level that meets your quality bar. That’s exactly what we did. How we tested We wanted a task hard enough for the thinking level to matter. So instead of small snippets, we asked for a complete game: “Neon Defense,” a tower defense game in a single HTML file. It had to include: - enemies that follow a winding path - 3 enemy types and 10 waves, with bosses on waves 5 and 10 - 3 tower types single-target, splash damage and slow - placement rules and upgrades to level 3 - a 70% sell refund - gold, lives and score - pause, 2x speed and restart - particles and screen shake - a best score saved in the browser - mouse and touch support - a fixed-timestep game loop that stays smooth with 100+ objects on screen The setup: - Model: Gemini 4 Argon in the Gemini app, on a Google AI Pro plan, in Chrome on a MacBook Air. - Runs: three runs Low, Medium, High , each in a new chat , with the exact same prompt . The full prompt is at the end of this article https://docs.google.com/document/d/1lJtv6vb7nXJlCWWKrttv4km-kakOBHCAW1-1vipwczM/edit bookmark=id.ojbtak17xaor . - Timing: each run was screen-recorded. We timed it from pressing Send until Gemini’s stop button disappeared, read from the recording at half-second steps. - Scoring: we played each saved game with an automated test bot in a real Chrome browser. The bot: - clicked through our 30-point checklist https://docs.google.com/document/d/1lJtv6vb7nXJlCWWKrttv4km-kakOBHCAW1-1vipwczM/edit bookmark=id.6ksbnrmczlnq - played all 10 waves with the same simple build strategy - did a second run with no towers to trigger game over - ran a stress test with 200+ enemies on screen - How the bot read the games: we added a small read-only hook to test copies, so the bot could read live game numbers gold, lives, wave, towers . For the stress test, the hook also added extra enemies. The games you can play below are the unedited originals. A few checks bosses costing 5 lives, splash damage and slow, particles and screen shake we verified in the code and by eye. The checklist says which method we used for each item. Result 1: High took almost twice as long, and Medium beat Low Bar chart of generation time for Gemini 4 Argon: Low 3:50, Medium 3:10, High 6:09 Time from Send to the finished answer, for the same prompt at each thinking level. | Thinking level | Time to finish | Answer complete? | Followed “code only, no extra text”? | |---|---|---|---| | Low | 3:50 230 s | Yes, ends with