Claude Opus Token Costs: Context Window vs Cost-Effectiveness [2026]
Claude Opus 4.8 is Anthropic's most capable Opus-tier model — highly autonomous, with a 1M token context window at standard pricing. Above it sits Fable 5, the most capable model overall, at double the per-token price. Below it, Sonnet 4.6 and Haiku 4.5 cover most everyday coding far more cheaply. This guide compares all four on context, pricing, and real cost-per-task, and shows which one cuts total costs for typical Claude Code work.
Claude model comparison: Context, speed, and cost
| Model | Context Window | Input/Output Cost | Speed | Best For |
|---|---|---|---|---|
| Haiku 4.5 | 200k tokens | Lowest ($1/$5 per 1M) | Fastest | Small tasks, quick turnarounds |
| Sonnet 4.6 | 1M tokens | Mid ($3/$15 per 1M) | Balanced | Most coding tasks, long sessions |
| Opus 4.8 | 1M tokens | High ($5/$25 per 1M) | Slower | Complex reasoning, agentic work |
| Fable 5 | 1M tokens | Highest ($10/$50 per 1M) | Slowest | Hardest reasoning, long-horizon agents |
What changed with the latest models?
- ✓Context window: Opus 4.8, Sonnet 4.6, and Fable 5 all offer 1M tokens; Haiku 4.5 offers 200k
- ✓Pricing: Opus 4.8 is $5/$25 per 1M — half the old Opus rate — at the full 1M window with no long-context premium
- ✓Fable 5: a new top tier above Opus for the hardest reasoning and autonomous agentic runs, at $10/$50 per 1M
- ✓Reasoning: Opus 4.8 and Fable 5 are tuned for long-horizon, multi-step agentic work that lesser models stall on
Cost per coding task: Real numbers
A typical Claude Code session with 20 tool calls across 10 files, lasting 30 minutes (roughly 120k tokens in, 15k out):
| Model | Tokens In | Tokens Out | Total Cost |
|---|---|---|---|
| Haiku 4.5 | 120k | 15k | $0.20 |
| Sonnet 4.6 | 120k | 15k | $0.59 |
| Opus 4.8 | 120k | 15k | $0.98 |
| Fable 5 | 120k | 15k | $1.95 |
Fable 5 costs roughly 10x more than Haiku for the same task. It delivers better reasoning on the hardest problems — but for most coding work (refactoring, debugging, test writing), Sonnet 4.6 is cheaper and fast enough, and Opus 4.8 handles complex agentic runs at half Fable's price.
Sonnet 4.6's 1M token window: Do you really need Opus or Fable?
Sonnet 4.6 has a 1M token context window, the same as Opus 4.8 and Fable 5. It can load entire large codebases in a single session at the lowest per-token rate of the three. The only reason to reach for Opus 4.8 or Fable 5 is better reasoning on complex, multi-step problems — not capacity. For raw token volume on routine work, Sonnet is the most cost-effective choice.
When to use each model in Claude Code
- ✓Haiku 4.5: Quick fixes, small scripts, low-stakes tasks. Fastest turnaround, 200k context.
- ✓Sonnet 4.6: Most coding work. Balanced speed, cost, and reasoning. 1M token window covers big codebases.
- ✓Opus 4.8: Complex reasoning and long-horizon agentic work. 1M context at half the old Opus price.
- ✓Fable 5: The hardest reasoning and most autonomous multi-step runs, when capability matters more than cost.
Reduce costs further with Token Limits proxy
Regardless of which model you choose, Token Limits proxy cuts token consumption 60-80% on tool outputs. That same 30-minute session drops from 135k tokens (120k+15k) to roughly 45k. Cost per session falls to about $0.07 (Haiku 4.5), $0.20 (Sonnet 4.6), $0.33 (Opus 4.8), and $0.65 (Fable 5).
- Install: curl -fsSL https://tokenlimits.app/api/install | bash (on Windows run it inside WSL, where Claude Code runs natively)
- Run: token-limits setup and paste your license key (free trial: 100 requests, no card needed)
- Setup starts the proxy on http://localhost:4800 and sets ANTHROPIC_BASE_URL in ~/.claude/settings.json so Claude Code routes through it
- Close and reopen Claude Code. Every tool result is now compressed before it reaches the model
- Verify: token-limits status, or open the dashboard at http://localhost:4800 and watch the request count climb
With Token Limits installed, Haiku becomes viable even for large tasks, Sonnet becomes almost free, and the top-tier models stay affordable on the runs that actually need them.
Cut Opus and Fable costs by up to 80% with Token Limits
Token Limits proxy compresses every grep, file read, and diff automatically. Same results, fraction of the token cost. Works with Haiku, Sonnet, Opus, and Fable.
FAQ
Is Opus 4.8 better for code than Sonnet 4.6?
For complex, multi-step or long-horizon agentic work, yes — Opus 4.8 reasons more thoroughly. But for most coding tasks (refactoring, testing, debugging), Sonnet 4.6 is equally capable and costs less than half as much. Use Opus where the reasoning gain earns its price.
How much does Fable 5 cost compared to Opus 4.8?
Fable 5 is $10/$50 per million tokens versus Opus 4.8 at $5/$25 — roughly double. Fable 5 is the most capable model for the hardest reasoning and autonomous agentic runs; Opus 4.8 covers most complex work at half the price.
Does Sonnet 4.6 really have a 1M token window?
Yes. Sonnet 4.6 has a 1M token context window, the same as Opus 4.8 and Fable 5. The main differences are pricing and reasoning quality, not capacity.
Should I use Haiku for coding?
Haiku 4.5 is fastest and cheapest with a 200k context window, but less accurate on complex tasks. It is great for quick fixes and small scripts. For full-featured development, Sonnet 4.6 is the sweet spot.
Does Token Limits proxy work with all models?
Yes. The proxy compresses tool outputs the same way regardless of model. Works with Haiku, Sonnet, Opus, Fable, and any Claude variant.