GPT-5.3 Codex vs GPT-6 Astra
Benchmark Performance
Available Benchmarks
Technical Differences
Side-by-Side Facts
| Field | GPT-5.3-Codex | GPT-6 Astra |
|---|---|---|
| Developer | OpenAI | OpenAI |
| Family | Gpt 5 3 | Gpt 6 |
| Model | GPT-5.3-Codex | GPT-6 Astra |
| Version | GPT-5.3-Codex | GPT-6 Astra |
| Lifecycle | active | active |
| Released | Unknown | 2026-09-03 |
| Knowledge cutoff | 2025-08-31 | 2026-04-30 |
| Input modalities | Text, Image | Text, Image |
| Output modalities | Text | Text |
| Context window | 400K | 1,050K |
| Total parameters | Unknown | Unknown |
| Active parameters | Unknown | Unknown |
| License | Unknown | Unknown |
| Open weights | No | No |
| API available | Yes | Yes |
| Self-hostable | No | No |
| Provider access | Openai (Standard), Openrouter (Standard) | Openai (Standard), Openrouter (Standard) |
| Capabilities | chat, generation, reasoning, structured_outputs, tools | chat, computer-use, generation, reasoning, research, tools |
14 comparable fields · 6 material differences · Pair passes the primary-source comparison gate
GPT-5.3 Codex Capabilities
GPT-6 Astra Capabilities
Internal Comparison Graph
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Primary Evidence
Sources and Freshness
Questions
GPT-5.3 Codex vs GPT-6 Astra FAQs
Is GPT-5.3 Codex or GPT-6 Astra better for coding?+
This comparison does not currently contain a protocol-matched coding benchmark for both GPT-5.3 Codex and GPT-6 Astra, so Model Markets cannot name a coding leader from pricing, context size, or capability labels alone.
Which is cheaper, GPT-5.3 Codex or GPT-6 Astra?+
GPT-5.3 Codex is $1.75 and GPT-6 Astra is $10.00 per million tokens, so GPT-5.3 Codex is cheaper on this metric. GPT-5.3 Codex is $14.00 and GPT-6 Astra is $50.00 per million tokens, so GPT-5.3 Codex is cheaper on this metric.
Which has a larger context window, GPT-5.3 Codex or GPT-6 Astra?+
GPT-6 Astra has the larger sourced context window. GPT-5.3 Codex supports 400K and GPT-6 Astra supports 1,050K.
Which performs better in benchmarks, GPT-5.3 Codex or GPT-6 Astra?+
There is no overall benchmark winner: At least two independently verified, protocol-matched benchmarks are required for an overall winner.
Can GPT-5.3 Codex or GPT-6 Astra be self-hosted?+
Both models have the same recorded self-hosting status: unsupported. GPT-5.3 Codex is not marked open weight; GPT-6 Astra is not marked open weight.
Can GPT-5.3 Codex and GPT-6 Astra understand images?+
GPT-5.3 Codex is documented with image input; GPT-6 Astra is documented with image input. This reflects supported input modalities, not vision quality.
Which can generate longer answers, GPT-5.3 Codex or GPT-6 Astra?+
Neither has a larger sourced maximum output. GPT-5.3 Codex is 128K and GPT-6 Astra is 128K.
Do GPT-5.3 Codex and GPT-6 Astra support reasoning and tool use?+
GPT-5.3 Codex: reasoning, tool calling, and image input. GPT-6 Astra: reasoning, tool calling, and image input. Feature support does not establish relative quality.
Which is available from more inference providers, GPT-5.3 Codex or GPT-6 Astra?+
GPT-5.3 Codex has 2 sourced provider routes; GPT-6 Astra has 2, a tie.
Which offers better value, GPT-5.3 Codex or GPT-6 Astra?+
There is no universal value winner. Compare the input and output prices above with the matched benchmark result for your workload: cheaper tokens can be offset by different quality, token usage, latency, or provider availability.