TokenRate
Article · Fundamentals4 min read

System Prompt Cost Across LLMs: Compare Prices Grid

How system prompts factor into per-call cost in TokenRate's Compare Prices grid — and why long system prompts compound across volume.

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Why System Prompt Pricing Matters in a Cost Comparison

TokenRate's new Compare Prices grid puts every model's per-token rates, context window, and quality score in a single side-by-side view. The point: stop flipping between provider pricing pages and OpenRouter tabs. You pick a provider dropdown, check the models you want, repeat for each provider, and the grid stacks every pick into one comparison table. Most teams compare LLMs on per-token input price and call it a day. System Prompt Pricing is one of the under-attended dimensions that shows up in the Compare Prices grid — and ignoring it is where the surprise bills come from. System prompts are input tokens. A 2,000-token system prompt × the model's input rate × every request = the system-prompt cost line in your monthly bill. See also: filter LLM models by tier, cost, quality, Value column vs tokens-per-dollar, and how to pick an LLM by quality score and cost.

How System Prompt Pricing Appears in the Grid

In the Compare Prices grid, the input cost column is what multiplies your system prompt. For a 2K-token system prompt and 1M requests/month at $1/M input, that's $2,000/month just in system prompt cost.

Reading the Spread

Prompt caching changes this. Most providers offer cached input at 10% of base. The Compare Prices grid shows base rates only — cached pricing modeling happens downstream in /tools/api-cost-estimator.

Practical Implications

For long system prompts, the right Compare Prices pick is whichever has the cheapest cached input (typically Anthropic Claude or Gemini). System prompts shouldn't drive the model choice — but they should drive whether caching is enabled.

Workflow: From Grid to Decision

Frequently Asked Questions

How do I open the Compare Prices grid?

Two ways: click the 'Compare Prices' tab at the top of the calculator card on the home page, or navigate directly to /tools/compare-prices. The standalone page is also linked from the main navigation under 'Tools'.

Can I share my comparison with teammates?

Yes — the page URL captures the current state. Send the link in Slack and your teammate sees the same grid. Useful for procurement and architecture-review meetings.

Is the data live or cached?

Live from OpenRouter (prices) and a blended Arena AI + Artificial Analysis pipeline (quality), refreshed on a 60-minute incremental cache. So the grid is at most an hour stale.

Where do I go after the grid to project monthly cost?

Once you've picked a winner, go to /tools/api-cost-estimator and plug in the model + your expected monthly token volume. The estimator does the per-1M math against your real workload mix.

Try the TokenRate Calculator

Run the comparison live at [/tools/compare-prices](/tools/compare-prices), then bookmark the URL for next month's price audit.

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