Both are OpenAI models. GPT-5.3-Codex is the newer, generally stronger default; reach for GPT-5.2 when a specific cost or latency profile matters more than the latest capabilities.
GPT-5.2 and GPT-5.3-Codex are both OpenAI models, so the real question is not which lab to trust but which tier fits your workload and budget. GPT-5.2 is a capable GPT-5-generation all-rounder, now succeeded by GPT-5.5. GPT-5.3-Codex is openAI's coding-specialized agent model for autonomous software engineering. Since both come from the same lab, the comparison below focuses on the tier-and-cost trade-offs that actually separate them.
Key differences
Context window: both advertise 400K (~600 pages). Tie on paper — test on your own long inputs, since usable recall varies by model.
Recency: GPT-5.3-Codex is the newer model by about 3 months (released February 24, 2026), usually meaning fresher training data and capabilities.
Specifications
Spec
GPT-5.2
GPT-5.3-Codex
Provider
OpenAI (US)
OpenAI (US)
Released
December 11, 2025
February 24, 2026
Context window
400K (~600 pages)
400K (~600 pages)
Price (in/out)
$1.75/$14 per 1M tokens
$1.75/$14 per 1M tokens
Open weight?
No — API only
No — API only
Modalities
text, image, code
text, code
SWE-Bench Verified
Not published
Not published
MRCR v2 @ 1M
Not published
Not published
Who wins what
Strong all-round reasoning: GPT-5.2 — GPT-5.2 lists strong all-round reasoning among its strengths; GPT-5.3-Codex does not.
Reliable structured output: GPT-5.2 — GPT-5.2 lists reliable structured output among its strengths; GPT-5.3-Codex does not.
Broad ecosystem and tooling: GPT-5.2 — GPT-5.2 lists broad ecosystem and tooling among its strengths; GPT-5.3-Codex does not.
Dedicated coding agent: GPT-5.3-Codex — OpenAI's coding-specialized agent model for autonomous software engineering — and it is the newer of the two.
CLI and IDE integration: GPT-5.3-Codex — GPT-5.3-Codex lists cLI and IDE integration among its strengths; GPT-5.2 does not.
Autonomous software tasks: GPT-5.3-Codex — GPT-5.3-Codex lists autonomous software tasks among its strengths; GPT-5.2 does not.
Which should you pick?
Anyone whose priority is strong all-round reasoning: GPT-5.2 — It is specifically built for that.
Anyone whose priority is dedicated coding agent: GPT-5.3-Codex — That is its strongest area.
GPT-5.2: where it fits
A capable GPT-5-generation all-rounder, now succeeded by GPT-5.5. Released December 11, 2025 by OpenAI, it is built for strong all-round reasoning, reliable structured output, broad ecosystem and tooling, and professional workflows.
Its trade-offs are real: superseded by GPT-5.5, and smaller context than flagships. At $1.75 in / $14 out per million tokens, it sits in the mid price band.
GPT-5.3-Codex: where it fits
OpenAI's coding-specialized agent model for autonomous software engineering. Released February 24, 2026 by OpenAI, it is built for dedicated coding agent, cLI and IDE integration, autonomous software tasks, and tool calling.
Its trade-offs: coding-specialized, narrower general use, and retired in favor of GPT-5.5 Codex. At $1.75 in / $14 out per million tokens, it sits in the mid price band.
The bottom line for this matchup
Because GPT-5.2 and GPT-5.3-Codex come from the same lab (OpenAI), they share the same training philosophy and ecosystem — the decision is purely tier vs. cost. GPT-5.3-Codex is the more capable, more recent option; the other earns its place only when its price or latency profile fits a specific job better. Most teams should default to GPT-5.3-Codex and drop down only with a concrete reason.
Frequently asked questions
Is GPT-5.2 or GPT-5.3-Codex better for coding?
Public SWE-Bench figures are not available for either model, so the honest test is your own repository — run an identical real bug through both. By design, GPT-5.2 leans toward strong all-round reasoning while GPT-5.3-Codex leans toward dedicated coding agent, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, GPT-5.2 or GPT-5.3-Codex?
They are priced almost identically, so cost will not decide between them.
Which has the bigger context window?
Both advertise 400K (~600 pages). Remember advertised ≠ usable: recall typically degrades before the ceiling.
Should I upgrade from GPT-5.2 to GPT-5.3-Codex?
Since both are OpenAI models, the newer one (GPT-5.3-Codex) is usually the better default unless you need a specific cost or latency profile from the other.
Which is newer, GPT-5.2 or GPT-5.3-Codex?
GPT-5.3-Codex — released February 24, 2026, about 3 months after GPT-5.2.
GPT-5.2 vs GPT-5.3-Codex
OpenAI · US | OpenAI · US · Updated June 2026
Quick verdict
Both are OpenAI models. GPT-5.3-Codex is the newer, generally stronger default; reach for GPT-5.2 when a specific cost or latency profile matters more than the latest capabilities.
GPT-5.2 and GPT-5.3-Codex are both OpenAI models, so the real question is not which lab to trust but which tier fits your workload and budget. GPT-5.2 is a capable GPT-5-generation all-rounder, now succeeded by GPT-5.5. GPT-5.3-Codex is openAI's coding-specialized agent model for autonomous software engineering. Since both come from the same lab, the comparison below focuses on the tier-and-cost trade-offs that actually separate them.
Key differences at a glance
▸Context window: both advertise 400K (~600 pages). Tie on paper — test on your own long inputs, since usable recall varies by model.
▸Recency: GPT-5.3-Codex is the newer model by about 3 months (released February 24, 2026), usually meaning fresher training data and capabilities.
Side-by-side specs
Spec
GPT-5.2
GPT-5.3-Codex
Provider
OpenAI (US)
OpenAI (US)
Released
December 11, 2025
February 24, 2026
Context window
400K (~600 pages)
400K (~600 pages)
Price (in/out)
$1.75/$14 per 1M tokens
$1.75/$14 per 1M tokens
Open weight?
No — API only
No — API only
Modalities
text, image, code
text, code
SWE-Bench Verified
Not published
Not published
MRCR v2 @ 1M
Not published
Not published
Who wins what
Strong all-round reasoning
GPT-5.2
GPT-5.2 lists strong all-round reasoning among its strengths; GPT-5.3-Codex does not.
Reliable structured output
GPT-5.2
GPT-5.2 lists reliable structured output among its strengths; GPT-5.3-Codex does not.
Broad ecosystem and tooling
GPT-5.2
GPT-5.2 lists broad ecosystem and tooling among its strengths; GPT-5.3-Codex does not.
Dedicated coding agent
GPT-5.3-Codex
OpenAI's coding-specialized agent model for autonomous software engineering — and it is the newer of the two.
CLI and IDE integration
GPT-5.3-Codex
GPT-5.3-Codex lists cLI and IDE integration among its strengths; GPT-5.2 does not.
Autonomous software tasks
GPT-5.3-Codex
GPT-5.3-Codex lists autonomous software tasks among its strengths; GPT-5.2 does not.
Which should you pick?
Anyone whose priority is strong all-round reasoning
→ GPT-5.2
It is specifically built for that.
Anyone whose priority is dedicated coding agent
→ GPT-5.3-Codex
That is its strongest area.
GPT-5.2: where it fits
A capable GPT-5-generation all-rounder, now succeeded by GPT-5.5. Released December 11, 2025 by OpenAI, it is built for strong all-round reasoning, reliable structured output, broad ecosystem and tooling, and professional workflows.
Its trade-offs are real: superseded by GPT-5.5, and smaller context than flagships. At $1.75 in / $14 out per million tokens, it sits in the mid price band.
GPT-5.3-Codex: where it fits
OpenAI's coding-specialized agent model for autonomous software engineering. Released February 24, 2026 by OpenAI, it is built for dedicated coding agent, cLI and IDE integration, autonomous software tasks, and tool calling.
Its trade-offs: coding-specialized, narrower general use, and retired in favor of GPT-5.5 Codex. At $1.75 in / $14 out per million tokens, it sits in the mid price band.
The bottom line for this matchup
Because GPT-5.2 and GPT-5.3-Codex come from the same lab (OpenAI), they share the same training philosophy and ecosystem — the decision is purely tier vs. cost. GPT-5.3-Codex is the more capable, more recent option; the other earns its place only when its price or latency profile fits a specific job better. Most teams should default to GPT-5.3-Codex and drop down only with a concrete reason.
Want both GPT-5.2 and GPT-5.3-Codex without two subscriptions? LumiChats gives you these plus 40+ models under one ₹69/day pass (about $1/day) — draft with one, cross-check with the other.
Public SWE-Bench figures are not available for either model, so the honest test is your own repository — run an identical real bug through both. By design, GPT-5.2 leans toward strong all-round reasoning while GPT-5.3-Codex leans toward dedicated coding agent, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, GPT-5.2 or GPT-5.3-Codex?
They are priced almost identically, so cost will not decide between them.
Which has the bigger context window?
Both advertise 400K (~600 pages). Remember advertised ≠ usable: recall typically degrades before the ceiling.
Should I upgrade from GPT-5.2 to GPT-5.3-Codex?
Since both are OpenAI models, the newer one (GPT-5.3-Codex) is usually the better default unless you need a specific cost or latency profile from the other.
Which is newer, GPT-5.2 or GPT-5.3-Codex?
GPT-5.3-Codex — released February 24, 2026, about 3 months after GPT-5.2.
Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.