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Cheapest LLM for 20 real workloads: actual token math (2026)

Published 15 July 2026 ยท reference prices, verify before budgeting

We took 20 real production workloads โ€” with realistic token counts for each โ€” and priced them across four model tiers at 1,000 requests/day. The difference between cheapest and most expensive model for identical tasks reaches 100ร— or more.

The four tiers we tested

ModelInput $/1MOutput $/1MTier
Gemini 2.0 Flash cheapest$0.10$0.40Small
GPT-4o mini$0.15$0.60Small
Claude Haiku 4.5$0.80$4.00Small+
GPT-4o$2.50$10.00Frontier
Claude Sonnet 4$3.00$15.00Frontier
Reference prices, July 2026. Always verify on the provider's pricing page. Track price changes โ†’

The 20 workloads at 1,000 requests/day

Monthly cost = requests/day ร— 30 ร— cost per request. Token counts are typical values โ€” your actual usage may differ. Use the calculator for your exact numbers.

Group 1: Classification and routing (short output)

WorkloadTokens (in/out)Flash/mo4o-mini/moHaiku/moGPT-4o/mo
Email classification100 / 20$0.54$0.81$4.80$18
Sentiment analysis150 / 30$0.81$1.22$7.20$27
News categorization60 / 10$0.30$0.45$2.70$10
Search query rewriting80 / 60$0.95$1.44$9.00$34
Content moderation500 / 20$1.74$2.61$15.60$58
Pattern: For short-output classification tasks, Gemini Flash is 30โ€“100ร— cheaper than GPT-4o. The quality difference for binary or small-set classification is usually undetectable in A/B tests. Flash is the obvious choice.

Group 2: Generation and drafting (longer output)

WorkloadTokens (in/out)Flash/mo4o-mini/moHaiku/moGPT-4o/mo
Email reply draft300 / 400$5.76$8.55$54$202
Product description200 / 300$4.14$6.21$39.60$148
Social media post200 / 120$2.02$3.06$19.20$71
FAQ answer400 / 350$5.40$8.10$51.60$193
User feedback summary600 / 200$4.20$6.30$38.40$142
Watch output costs: Once output tokens rise (350โ€“400+), the output price dominates. GPT-4o's $10/1M output vs Flash's $0.40/1M is a 25ร— difference โ€” that multiplies fast.

Group 3: Customer support and chat

WorkloadTokens (in/out)Flash/mo4o-mini/moHaiku/moSonnet 4/mo
Support chat message500 / 300$5.10$7.65$48$180
Support chat (with history)2000 / 300$9.60$14.40$87.60$315
Complaint escalation decision800 / 100$3.60$5.40$33.60$126

Context growth is the hidden cost. As conversation history accumulates, input tokens balloon. Message 1 might be 300 tokens; message 10 in the same chat might be 2,500 tokens. That's an 8ร— increase in the input cost alone โ€” see our full analysis of conversation cost growth.

Group 4: Code and reasoning (quality-sensitive)

WorkloadTokens (in/out)Flash/mo4o-mini/moHaiku/moGPT-4o/mo
SQL query generation400 / 200$3.60$5.40$33.60$126
Code review comment600 / 800$12.36$18.54$117.60$441
Bug fix explanation800 / 1000$14.40$21.60$138$516
Unit test generation600 / 1200$16.20$24.30$166.80$625
Quality threshold matters here. For code tasks, a wrong or insecure output has real cost โ€” debug time, security risk. Benchmark your use case before assuming Flash or 4o-mini are good enough. For many code review / generation tasks, GPT-4o or Sonnet 4 performance justifies the price. For SQL on a well-defined schema, Flash often passes evals.

Group 5: Long-context (RAG, summaries, legal)

WorkloadTokens (in/out)Flash/mo4o-mini/moHaiku/moGPT-4o/mo
RAG answer (3 chunks)2000 / 400$10.80$16.20$102$381
Document summarization4000 / 500$18$27$156$585
Legal clause extraction8000 / 1000$35.60$54$336$1,260
Invoice data extraction1000 / 300$6.60$9.90$58.80$220

At large context sizes, input cost becomes the dominant term. With a legal document at 8,000 input tokens, Gemini Flash costs $35.60/month at 1k req/day โ€” GPT-4o costs $1,260. For extraction tasks (structured output, well-defined schema), Flash and 4o-mini typically perform well. For open-ended reasoning over long docs, test quality carefully.

The headline finding

Across all 20 workloads, switching from GPT-4o to Gemini Flash for simple classification saves 95โ€“97%. On code generation with long output (unit tests, bug fixes), the saving is still 97%. The absolute dollar amounts vary โ€” $0.30/month for news categorization vs $625/month for unit tests โ€” but the multiplier is consistent.

The practical implication: don't use one model for everything. Run frontier models on tasks where quality objectively matters (measured by your eval), and use small models for routing, classification, and extraction where benchmarks show they match.

What this means in practice

Task typeRecommended tierReasoning
Classification / routingFlash or 4o-miniOutput quality meets threshold at 5% of the cost
Short generation (<200 tokens)Flash or 4o-miniQuality usually acceptable; test first
Support chatFlash or HaikuContext costs grow fast; Flash wins on volume
SQL / code (well-defined)4o-mini or HaikuBetter than Flash for structured output; much cheaper than frontier
Complex reasoning / codeGPT-4o or Sonnet 4Quality gap is real and measurable; budget accordingly
Long-context extractionFlash or 4o-miniSchema-driven tasks don't need frontier reasoning
Long-context analysisGPT-4o or Gemini 2.5 ProOpen-ended reasoning over 8k+ tokens needs frontier capability

Run your own numbers

All of the above assumed 1,000 requests/day. Scale linearly: 10,000 req/day = 10ร— the costs; 100 req/day = 10% of the costs. Use our LLM cost calculator or compare specific models at LLM price comparison.

Reference prices, July 2026. LLM prices change frequently. Always verify on the provider's pricing page before finalising a budget. Found an error? Report it โ†’