Verified 2026 API Rates • Prompt Caching & Batch ROI

Claude 3.5 Sonnet vs OpenAI o3-mini

Compare real-world API costs for Claude 3.5 Sonnet ($3/$15) vs OpenAI o3-mini ($1.1/$4.4). Calculate Prompt Caching ROI & Batch API savings.

OpenAI o3-mini saves up to 63% on base input tokens
Anthropic

Claude 3.5 Sonnet

claude-3-5-sonnet
Base Input Rate
$3.00 / 1M
Output Rate
$15.00 / 1M
Prompt Cache Read
$0.30 / 1M (-90%)
Cache Write Surcharge
$3.75 / 1M (+25%)
Batch API Discount
-50% Off
Context Window
200k tokens
Quality Index (MMLU)
88.3
OpenAI

OpenAI o3-mini

o3-mini
Base Input Rate
$1.10 / 1M
Output Rate
$4.40 / 1M
Prompt Cache Read
$0.55 / 1M (-50%)
Cache Write Surcharge
$0.00 (Free write)
Batch API Discount
-50% Off
Context Window
200k tokens
Quality Index (MMLU)
89
Differential Module 1

Prompt Caching ROI & Write Surcharge Break-Even Analysis

Prompt caching drastically reduces input token costs for static prefixes like system prompts, tool schemas, and document chunks. Compare caching mechanisms between Claude 3.5 Sonnet and OpenAI o3-mini:

Claude 3.5 Sonnet Caching Profile-90% read discount

  • Cached Read Price: $0.300 per 1M tokens.
  • Write Surcharge: $3.75/1M (+25% fee on initial cache write).
  • Minimum Cache Prefix: 1,024 tokens.
  • Amortization Rule: Net cost savings begin when prefix is reused > 1.25 times within TTL.

OpenAI o3-mini Caching Profile-50% read discount

  • Cached Read Price: $0.550 per 1M tokens.
  • Write Surcharge: $0.00 (automatic caching with zero write penalty).
  • Minimum Cache Prefix: 1,024 tokens.
  • Amortization Rule: Immediate net savings from first cached read call.
Differential Module 2

Batch API 50% Discount Offload vs Real-Time SLA

Asynchronous Batch APIs cut total token expenditures in half (50% off input and output) in exchange for non-realtime execution (up to 24-hour turnaround SLA).

Model / ArchitectureStandard Input / OutputBatch 50% Off Input / OutputTurnaround SLAOptimal Use Cases
Claude 3.5 Sonnet$3.00 / $15.00$1.50 / $7.50 (-50%)24 Hours max (typically 30m - 2h)Bulk evaluation, dataset labeling, background summarization
OpenAI o3-mini$1.10 / $4.40$0.55 / $2.20 (-50%)24 Hours max (typically 30m - 2h)Offline document translation, embedding backfills, test suites
Differential Module 3

Context Window Escalation & Tiered Pricing Architecture

Massive context windows allow ingesting entire repositories or books, but pricing models differ drastically between flat-rate vendors and tiered step-up pricing.

Claude 3.5 Sonnet Context Capacity

Provides a 200k token context window with a maximum output limit of 8.192k tokens.✓ Flat-rate billing across all prompt sizes up to max context ceiling.

OpenAI o3-mini Context Capacity

Provides a 200k token context window with a maximum output limit of 100k tokens.✓ Flat-rate billing across all prompt sizes up to max context ceiling.

Quill Strategic Content

Real-World Production Scenarios: Monthly Spend Projections

Pre-computed monthly engineering bill projections across 3 representative enterprise application workloads:

Scenario 1

RAG Knowledge Base & Enterprise Search

100,000 queries/month, 3,500 input tokens (system + 5 retrieved chunks), 400 output tokens, 75% prompt cache hit rate.

Claude 3.5 Sonnet:$993.75/mo
OpenAI o3-mini:$416.63/mo
Delta Savings:-$577.13 (58%)
Architecture Verdict:OpenAI o3-mini delivers 58% lower monthly spend ($577.13/mo savings) for this workload profile.
Scenario 2

Multi-Turn Coding Agent & ReAct Loops

25,000 tasks/month, 8,000 input tokens (accumulating conversation context & tool schemas), 1,200 output tokens, 85% cache hit rate.

Claude 3.5 Sonnet:$574.43/mo
OpenAI o3-mini:$239.11/mo
Delta Savings:-$335.31 (58%)
Architecture Verdict:OpenAI o3-mini delivers 58% lower monthly spend ($335.31/mo savings) for this workload profile.
Scenario 3

High-Throughput Offline Data Extraction

500,000 records/month, 1,500 input tokens, 250 output tokens, 100% batch offload (24-hour turnaround SLA).

Claude 3.5 Sonnet:$1916.25/mo
OpenAI o3-mini:$646.25/mo
Delta Savings:-$1270.00 (66%)
Architecture Verdict:OpenAI o3-mini delivers 66% lower monthly spend ($1270.00/mo savings) for this workload profile.
毫秒級即時互動模擬引擎

Claude 3.5 Sonnet 對比 OpenAI o3-mini

針對企業典型三大工程落地形態(RAG 知識庫、Coding Agent 多輪、離線批次清洗)進行精確成本演算:

Live 50ms Engine
月度請求量 (Requests)100,000
單次輸入代幣 (Input Tokens)4,000
單次輸出代幣 (Output Tokens)1,000
Prompt 快取命中率 (Cache Hit)70%
Batch API 批次分流比例0%
OpenAI o3-mini 更便宜

預計每月節省

Claude 3.5 Sonnet$2,004.00$20.040// 千次請求
對比
OpenAI o3-mini$726.00$7.260// 千次請求
Developer FAQs

Frequently Asked Questions: Claude 3.5 Sonnet vs OpenAI o3-mini

Authoritative answers on API rate limits, pricing math, break-even thresholds, and architectural migration.

1Which model is cheaper overall: Claude 3.5 Sonnet or OpenAI o3-mini?

At base pricing, Claude 3.5 Sonnet costs $3/1M input and $15/1M output, while OpenAI o3-mini costs $1.1/1M input and $4.4/1M output. The cheaper option depends on your input-to-output token ratio and whether prompt caching or batch discounts are utilized.

2How does Prompt Caching impact the cost of Claude 3.5 Sonnet vs OpenAI o3-mini?

Claude 3.5 Sonnet offers a 90% read discount ($0.3/1M), whereas OpenAI o3-mini provides a 50% read discount ($0.55/1M). High cache hit ratios (>70%) significantly compress the cost delta in agentic and RAG architectures.

3Can I use Batch API with Claude 3.5 Sonnet or OpenAI o3-mini to save 50%?

Claude 3.5 Sonnet supports 50% batch offload discounts for asynchronous 24-hour turnaround tasks. OpenAI o3-mini supports 50% batch discounts.

4What are the context window limits and tiered pricing rules for Claude 3.5 Sonnet vs OpenAI o3-mini?

Claude 3.5 Sonnet features a 200k context window with flat per-token pricing. In comparison, OpenAI o3-mini supports 200k tokens with flat per-token pricing.