Claude Sonnet 4.5 review: the coding model I actually pay for

After switching between GPT-4o, Gemini and Claude for a month of real work, Claude Sonnet 4.5 is the model I keep coming back to — and the one I actually pay for.

TL;DR

• Best-in-class coding and agentic tool use
• 200K context handles large codebases comfortably
• $3 / $15 per 1M tokens is mid-tier, but the output quality justifies it

"It's the first model where I trust the refactors it suggests without re-reading every line."

What it's great at

1. Agentic coding

Paired with Claude Code, it plans, edits and tests multi-file changes in a way that feels like a junior engineer — not a chatbot.

2. Long-context reliability

I dumped a 60K-line repo into context and asked it to trace a bug. It found the culprit in a single pass.

3. Honest about uncertainty

Unlike some models that confidently hallucinate, Sonnet 4.5 says "I'm not sure" — which matters more than raw benchmark scores.

Where it falls short

• Rate limits during peak hours are real
• Image generation is not its strength

The math

Plan	Price	Verdict
API (1M tokens)	$3 in / $15 out	Fair for the quality
Claude Pro	$20/mo	The sweet spot for most devs

Verdict

Worth it. For anyone writing code daily, this is the safest $20 you can spend on AI right now.