GPT-5.3 Codex vs GPT-5.5 Instant
Pricing verdict: GPT-5.3 Codex vs GPT-5.5 Instant: GPT-5.3 Codex is cheaper for input-heavy usage ($1.75/M vs $5.00/M input tokens), while GPT-5.5 Instant is better for long-context tasks (1,050,000 tokens).
Direct answer: choose GPT-5.3 Codex for lower token spend and choose GPT-5.5 Instant when your workload needs longer context.
Compare API pricing, input and output token costs, context windows, and monthly estimates on one page so you can pick the cheaper model fast.
Cost Comparison (1000 input + 500 output tokens, 100 requests/day)
GPT-5.3 Codex
GPT-5.5 Instant
Cost Differences
GPT-5.5 Instant costs more than GPT-5.3 Codex
Quick Recommendation
Winner for direct API pricing: GPT-5.3 Codex. At the default workload, GPT-5.3 Codex saves about $33.75/month ($410.625/year) versus GPT-5.5 Instant.
Feature Comparison
| Feature | GPT-5.3 Codex | GPT-5.5 Instant |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Input Price | $1.75/1M tokens | $5.00/1M tokens |
| Output Price | $14.00/1M tokens | $30.00/1M tokens |
| Context Window | 256,000 tokens | 1,050,000 tokens |
| Max Output | 32,768 tokens | 128,000 tokens |
| Category | coding | flagship |
| Capabilities | textcode | textvisioncodereasoning |
| Release Date | 3/1/2026 | 5/5/2026 |
GPT-5.3 Codex vs GPT-5.5 Instant: Which Should You Choose?
Choosing between GPT-5.3 Codex and GPT-5.5 Instant depends on your priorities: cost efficiency, context length, or raw capability. GPT-5.3 Codex is the more affordable option at $1.75/1M input tokens — 65% cheaper than GPT-5.5 Instant. Meanwhile, GPT-5.5 Instant offers a significantly larger context window at 1,050,000 tokens vs 256,000 for GPT-5.3 Codex.
These models target different tiers: GPT-5.3 Codex is a coding model while GPT-5.5 Instant is flagship. This means they're optimized for different workloads. GPT-5.5 Instant targets more demanding workloads, while GPT-5.3 Codex provides a cost-effective option for everyday tasks.
Output costs matter too. GPT-5.3 Codex charges $14.00/1M output tokens vs $30.00 for GPT-5.5 Instant. For generation-heavy workloads (content creation, code generation, summarization), output pricing often dominates your bill. GPT-5.3 Codex has the edge here at $14.00/1M output tokens.
Multimodal capabilities: GPT-5.5 Instant supports vision (image inputs) while GPT-5.3 Codex is text-only. If your application needs image understanding, this narrows your choice.
Best Use Cases
Choose GPT-5.3 Codex when:
- • Budget is a primary concern
- • You're already using OpenAI's API ecosystem
Choose GPT-5.5 Instant when:
- • You need a larger context window (1,050,000 tokens)
- • You need more capabilities (vision, reasoning)
- • You need longer outputs (up to 128,000 tokens)
- • You're already using OpenAI's API ecosystem
Pros and Caveats at a Glance
GPT-5.3 Codex
- • Input pricing: $1.75/M tokens
- • Output pricing: $14.00/M tokens
- • Context window: 256,000 tokens
- • Max output: 32,768 tokens
Watch out for
- • Smaller context window than GPT-5.5 Instant
GPT-5.5 Instant
- • Input pricing: $5.00/M tokens
- • Output pricing: $30.00/M tokens
- • Context window: 1,050,000 tokens
- • Max output: 128,000 tokens
Watch out for
- • Higher input cost than GPT-5.3 Codex
- • Higher output cost than GPT-5.3 Codex
Try Different Scenarios
Use the calculator below to see how costs change with different usage patterns
GPT-5.3 Codex (OpenAI)
GPT-5.5 Instant (OpenAI)
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