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LLM Toolkit

Model comparison

GPT-5 vs GPT-4o

Verified pricing, context windows and real-workload costs for both models — computed from official provider rates as of 2026-08-25.

Cheaper input

GPT-5

$1.25 /1M in

Cheaper output

GPT-5

$10.00 /1M out

Bigger context

GPT-5

400K tokens

Head to head

Spec GPT-5 GPT-4o
Input / 1M tokens $1.25 $2.50
Cached input / 1M $0.13 $0.63
Output / 1M tokens $10.00 $10.00
Context window 400K 128K
Provider OpenAI OpenAI
Price verified 2026-08-25 2026-08-25

Monthly cost at three real workloads

Workload GPT-5 GPT-4o Winner
Side-project chatbot 30K req · 2,000 in / 500 out · 40% cached $198.00/mo $255.00/mo GPT-5
Coding agent 500K req · 12,000 in / 1,500 out · 70% cached $10,275/mo $14,625/mo GPT-5
Bulk extraction 2,000K req · 800 in / 120 out · 20% cached $4,040/mo $5,800/mo GPT-5

Computed from list prices verified 2026-08-25. Cache savings blend normal and cached input rates by the hit rate; models without published cached rates use the base input price. Adjust every parameter yourself on the API Cost Calculator.

Pick GPT-5 if…

  • Input cost dominates your bill — it charges $1.25 per 1M input vs $2.50.
  • You need the larger 400K context window.
  • You run repeat-context workloads — cached input at $0.13 per 1M is the better deal.

Pick GPT-4o if…

  • Output-heavy agent loops favor its $10.00 output rate.
  • Its 128K window covers your typical request with headroom.
  • You want cheaper total spend at your exact volumes — verify with the calculator above.

Frequently asked questions

Is GPT-5 cheaper than GPT-4o?

GPT-5 is cheaper on input at $1.25 per 1M tokens vs $2.50 — input pricing is 2.0× less expensive. On output, GPT-5 wins at $10.00 vs $10.00. At a balanced workload (100K requests, 2K in / 500 out), GPT-5 runs $750.00/mo vs $1,000/mo — a 1.3× difference.

GPT-5 vs GPT-4o: which has the bigger context window?

GPT-5, with 400K tokens vs 128K — 3.1× more room. Filling GPT-5's window once costs $0.500 at list price, vs $0.320 for the smaller window.

Should I switch from GPT-5 to GPT-4o?

Switch if your bottleneck matches GPT-4o's strengths: its 128K context fits your documents and its pricing profile. Stay on GPT-5 if input cost dominates your bill — GPT-5 charges $1.25 per 1M in. Test both with your real token counts before committing.

Keep comparing

Or measure your real usage with the AI Token Counter and browse all rates on the Pricing Comparison.