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SOLVENCY

Head to head

GPT-5.3 Codex vs o3

GPT-5.3 Codex: currento3: legacyheavy tier

No verdict

Cost per solved task needs a published pass rate for both models. At least one has none, so it is reported as missing rather than estimated.

verified 2026-08-21 · prices from each provider's pricing page

Input $/M tokens

lower is better

  • GPT-5.3 Codex$1.75
  • o3$2

Output $/M tokens

lower is better

  • GPT-5.3 Codex$14
  • o3$8

Cost per solved task

needs a pass rate for both

  • GPT-5.3 Codexmissing
  • o3$1.99
GPT-5.3 Codexo3
Input $/Mtok$1.75$2
Output $/Mtok$14$8
Cached input $/Mtok$0.175$0.5
Pass ratemissing81%
Pass rate sourcemissingAider
Cost basismissingmodelled
Cost per solved taskmissing$1.99

verified 2026-08-21 · heavy task tier; measured rows ignore the tier· Methodology· GPT-5.3 Codex· o3