Gemini 2.5 Pro Review — I Used It as My Main AI for 5 Days Instead of Claude

Every month some new model "tops all benchmarks" and then I try it and it's fine but not worth switching anything. I've been burned enough times that I started ignoring these announcements.

Gemini 2.5 Pro was different — it was showing up at number one on SWE-bench (coding), MMLU (general reasoning), and a few others simultaneously. That's unusual. Usually a model wins one category and loses another. Winning multiple at once either means it's genuinely good or the benchmarks are being gamed. I needed to know which.

I've been on Claude for most of my work. It follows instructions precisely and handles large files well, which matters for my projects. Switching away from something that works feels wasteful. So I gave myself a rule: 5 days, Gemini 2.5 Pro only, real work only. No going back to Claude mid-session.

It's a "thinking" model, which means it reasons through a problem internally before giving you a response. You see a little "thinking" animation. Claude 3.7 and OpenAI's o-series models do the same thing. The idea is it catches mistakes in its own reasoning before showing you the answer.

Context window is 1 million tokens — genuinely massive. Free on gemini.google.com with daily limits. For developers, Google AI Studio (aistudio.google.com) gives API access for free with generous rate limits. Paid is through Google One AI Premium, which in India works out to roughly ₹1650/month on current pricing.

First real test was a problem I'd been avoiding. A React component where state was behaving wrong — the value was updating in one place but not reflecting in a child. The logic was spread across three files and I'd been putting it off because untangling it felt annoying.

I pasted all three files and described what was happening. Gemini 2.5 Pro identified the issue — a stale closure in a useCallback that wasn't being refreshed when a dependency changed — and explained why before giving the fix. The explanation was right. The fix worked first try.

That "explain before fixing" pattern is what I was used to with Claude. Gemini matching it on day one was a good sign. I stayed curious.

The thinking mode is slower. Obviously, since it's doing more work. But the problem is it thinks for everything — even stuff that doesn't need 12 seconds of internal reasoning.

I asked it what the CSS property was to make a div horizontally scrollable on overflow. It thought about it for 9 seconds. Nine seconds for a CSS property. I know this sounds petty but when you're doing rapid back-and-forth, those waits stack up in a way that gets genuinely irritating by day three.

I ended up using Perplexity for quick factual lookups and saving Gemini for things that actually deserved the thinking time. That helped. But it's something to know going in.

Day three I tested the 1M token context window on purpose. Pasted every relevant file from a Next.js project and asked it to find where a specific prop was getting dropped between components. The prop was being lost at a component boundary on what was effectively page 4 of the pasted content.

It found it. Correctly. And explained why the prop wasn't being forwarded. Claude is also good at large context, but Gemini 2.5 Pro felt slightly more reliable at actually reading and using the later parts of a long paste — not just the beginning.

For anyone who regularly pastes big files into AI chats, this difference is real.

Day four. I was asking about a specific JavaScript closure behaviour in an async context — slightly obscure edge case. Gemini 2.5 Pro answered with full confidence, walked through the reasoning, gave me code. The explanation sounded airtight.

I tested it. The code did not behave the way it said. I went back, told it what happened, and it corrected itself. The correction was accurate.

This is the thing people don't say enough about thinking models: they can be confidently wrong. The thinking process improves average accuracy but doesn't make the model infallible. Test anything that matters before trusting it.

I used both for writing tasks during the 5 days. Gemini 2.5 Pro writes clean, well-structured content. For technical explanations, documentation, comparisons — it's excellent.

For blog writing or anything where you want some actual personality, Claude's output still feels more natural to me. Gemini's writing is polished in a way that reads slightly "assembled." Not bad, just more neutral. Whether that matters depends on what you're writing.

One real advantage Gemini has: it pulls from live Google Search. Ask it about something that happened last week and it knows. Claude has a training cutoff. For research tasks where recency matters, Gemini wins clearly.

Free tier on gemini.google.com is usable but limited. For heavy daily use you'll hit the cap.

The actual good news is Google AI Studio — it's free, gives you API access to Gemini 2.5 Pro, and the rate limits are generous enough for personal projects and experimentation. If you're a developer, start there before paying for anything.

Google One AI Premium is around ₹1650/month in India right now. Claude Pro is around ₹1700. If you're choosing one paid subscription and your work involves large context or real-time information, Gemini 2.5 Pro is worth considering seriously.

I didn't fully switch. But I use it more than I expected to.

Gemini 2.5 Pro is now my first pick when: the task involves pasting large files, I need information from the past few weeks, or I'm doing research that benefits from live search. Claude stays my default for: writing with personality, anything requiring strict instruction-following ("only change this function"), and complex debugging where I want an explanation-first approach that's slightly more reliable.

The benchmarks reflect something real. It's not hype. Whether it's better than Claude depends entirely on what you're doing with it.