Tools & instruments
LLM API cost calculator
Price any workload across nine models at once: pick a task profile or paste your own prompt, set daily volume, compare the bills.
AI gateway fee calculator
Enter monthly spend, get each gateway's annual fee cost sorted cheapest first, with the flat-vs-percentage crossover called out.
The Verbosity Index
Output tokens billed for identical work, measured across models monthly. Edition 1: Opus 5 writes 48% above the task median; its same-priced predecessor writes 8% below.
Verbosity Index Edition 2: the tokenizer confound
72 fresh metered runs across six models including Fable 5.1, and a correction to Edition 1: one model was not counting tokens the same way. Both indices published.
We graded the OpenRouter listicles
Eight pages that rank for OpenRouter alternatives, every fee claim checked against the primary source the same day. Three correct, two wrong, three silent. Including our own ten-day error.
The price increase that did not happen
Sonnet 5's 50% increase was scheduled for September 1 and cancelled on August 25. What it would have cost, and the countdown clock we had running to a non-event.
Why your bill does not match your math
Five measured gaps between rate-card arithmetic and your invoice, including one nobody has priced in: the tokenizer changed.
The complete guides
LLM API pricing: the complete guide
Every major model's rates, what real tasks cost in metered bills, and the two discounts almost everyone leaves unused. The hub for all our pricing coverage.
LLM gateways: the complete guide
The four gateway types, real fees, our measured +68ms hop latency, and the selection question nobody prices. The hub for all our gateway coverage.
Routers & gateways
OpenRouter alternatives in 2026: an honest comparison from a competitor
Real fees, measured gateway latency, a which-gateway quiz that will happily recommend our competitors, and the category's open secret: the fee is not the money.
LiteLLM alternatives: when self-hosting stops being free
What free actually costs in ops time, and the managed options for teams whose constraint changed.
Portkey alternatives: control plane, gateway, or neither
Portkey charges for visibility, not tokens. The alternatives depend on which direction you came from, and whether the bill was the real problem.
Model pricing & comparisons
Opus 4.8 vs Opus 5: same price, 77% different bills
Identical rate cards, identical six-task battery, measured twice on each: the newer flagship billed 77% more, entirely through token count.
GPT-5.6 Sol vs Terra vs Luna: which tier does what
Three names, one family: what each tier costs, which traffic belongs where, and the trap in splitting tiers by hand.
Fable 5 pricing, explained: real bills from real requests
The flagship breakdown: measured side-by-sides with playable outputs, a real Claude Code session ledger, the full market ladder, a paste-your-prompt calculator, and the price-history answer to whether it gets cheaper.
Fable 5 alternatives: what actually comes close
Opus 5 at half price, GPT-5.6 Sol, Sonnet 5, batching the model you already use, and Pareto's blended model. What each costs and what you give up.
Claude Opus 5 pricing: same rate card, bigger bills
$5/$25, unchanged from 4.8. The measured surprise: the identical prompt billed 60% more on Opus 5, because verbosity is a price.
Claude Opus 4.8 pricing: the quiet bargain in Anthropic's ladder
Same price as its successor, fewer tokens per task in our meters. Why the previous flagship is still worth pricing, with the benchmark receipts anchored to it.
Claude Sonnet 5 pricing: $2/$10 is now permanent
The 50% increase scheduled for September 1 was cancelled and $2/$10 became standard. The Terra comparison and measured task bills for the mid tier.
GPT-5.6 Sol pricing: the frontier tier with an output premium
$5/$30: input tied with Opus 5, output 20% higher, and generation work is output-heavy. The cache math and the market table.
GPT-5.6 Luna pricing: the volume-tier bake-off
Luna at $1/$6 versus Haiku 4.5 at $1/$5. At a million tasks a month the gap is real money, and quality cliffs cost more than rates.
OpenAI API alternatives in 2026: what each one costs
Anthropic's ladder rung for rung, the open-weights math, and gateways. Every price verified and dated.
Anthropic API alternatives in 2026: prices and trade-offs
Start with the alternatives inside Anthropic: batch, cache, and tier down. Then the OpenAI comparison and what migration actually costs.
Guides & hubs
Best LLM gateway in 2026, ranked with receipts · Unbiased for your team
Compare any two models
List rates and dated competitor measurements: prices and measured bills. Pareto 26.9 measured task costs are not published. Verbosity: Edition 2.