GPT-5.3
GPT-5.3 is a large language model first observed on February 26, 2026, catalogued under multiple concurrent aliases including GPT-5.2, GPT-5.4, Vortex, and Zenith. It achieves a GPQA score of 92.0 and an SWE-bench Pro score of 56.8, with pricing set at $1.75 per million input tokens and $14.00 per million output tokens. No official release notes, parent entity confirmation, or version lineage documentation accompanied its appearance, leaving its generation placement and relationship to prior or subsequent models unverified. The model series includes specialized variants such as GPT-5.3-Codex, its most capable agentic model for autonomous software development. GPT-5.3 matters now because its benchmark and pricing coordinates, fixed to a 2026-02-26 observation date, provide a verifiable reference point for evaluating cost-capability trade-offs, while its unresolved naming multiplicity presents a documented case for model identity tracking and procurement verification.
OpenAI's GPT-5.3, catalogued under aliases including GPT-5.2, GPT-5.4, Vortex, and Zenith, presents a fragmented identity. Deployed on February 26, 2026, it uses RLHF, Sparse MoE, and Chain-of-Thought, but its GPQA score of 92.0 and SWE-bench Pro of 56.8 lag behind competitors—Microsoft's MAI-Cyber-1-Flash, which uses GPT-5.3, hits 96% on CyberGym. Recent headlines show GPT-5.4 scoring only 11.36% on PlanBench-XL hard tasks, while GPT-5.5 ties Claude Mythos in enterprise cyber tests. Downstream models ReMMD-Agent and MAI-Cyber-1-Flash rely on GPT-5.3, yet their performance suggests the base model's ceiling. With pricing at $1.75/M input tokens and $14.00/M output, GPT-5.3's economics may not justify its middling benchmarks.
- ·GPT-5.3 ships under multiple aliases (GPT-5.2, GPT-5.4, Vortex, Zenith), confusing market positioning.
- ·GPQA 92.0 and SWE-bench Pro 56.8 trail Microsoft's MAI-Cyber-1-Flash (96% CyberGym).
- ·ReMMD-Agent and MAI-Cyber-1-Flash depend on GPT-5.3, but its benchmarks limit their ceiling.
- ·GPT-5.4 struggles on PlanBench-XL (11.36%), while GPT-5.5 ties Claude Mythos in cyber tests.
- ·Pricing at $1.75/$14.00 per million tokens faces pressure from stronger competitors.
Signal Radar
Five-axis snapshot of this entity's footprint
Mentions × Lab Attention
Weekly mentions (solid) and average article relevance (dotted)
Timeline
10- Research MilestoneApr 18, 2026
Achieved 78.5% score on SWE-Bench coding benchmark
View source- score:
- 78.5%
- benchmark:
- SWE-Bench
- Research MilestoneApr 16, 2026
Observed autonomously optimizing an embedding model for Qualcomm NPU for three hours.
View source - Research MilestoneMar 26, 2026
Achieved 100% resident identification accuracy in a safety evaluation for a care home smart speaker system.
View source- accuracy resident id:
- 100%
- accuracy reminder recognition:
- 89.09%
- accuracy calendar conversion:
- 84.65%
- Product LaunchMar 7, 2026
Released as OpenAI's most capable frontier model with unified coding, reasoning, and computer operation capabilities
- benchmark score:
- 83.0% on GDPval
- Research MilestoneMar 6, 2026
Demonstrated surpassing human baselines on OSWorld benchmark with 75% score
View source- score:
- 75%
- Product LaunchMar 5, 2026
OpenAI releases GPT-5.4 with native computer use, tool search, and 1M token context window
View source- pricing:
- $2.50/$15 per million tokens (base), $30/$180 (Pro)
- Research MilestoneFeb 28, 2026
Identified as experiencing up to 33% accuracy degradation in extended conversations according to new research
View source- degradation rate:
- up to 33%
- task categories:
- 6
- Research MilestoneFeb 26, 2026
Appeared for public testing on the LM Arena benchmark platform under the codename 'Vortex and Zenith'.
Relationships
8Developed
Developed By
Uses
Deploys
Frequently appears with
10Entities that show up in the same articles — shared coverage, not a stated relationship.
Recent Articles
2Microsoft MAI-Cyber-1-Flash Hits 96% on CyberGym
+Microsoft's MAI-Cyber-1-Flash scores 96% on CyberGym, cutting costs 50% by handling 90% of security tasks locally while routing complex cases to GPT-5
100 relevanceBenchmark lets image models answer in pixels, not text
~New 'Show, Don't Tell' benchmark tests spatial cognition via pixel-level outputs. GPT Image 2 solves 37% of cases missed by GPT-5.4, highlighting a ga
85 relevance
Predictions
1- correctweekMar 29, 2026
OpenAI will ship a Codex workflow automation update within 2 weeks
Codex is surging and its cascade explicitly hits OpenAI, ChatGPT Instant Checkout, GPT-5.3-Codex, and Azure AI. The live web context says OpenAI already upgraded Codex to automate workflows and compete more directly with Claude Code, which makes a follow-on release or plugin expansion highly likely rather than a one-off announcement.
58%
AI Discoveries
2- observationactive22h ago
Lifecycle: GPT-5.3
GPT-5.3 is in 'active' phase (1 mentions/3d, 2/14d, 44 total)
90% confidence - observationactiveJul 18, 2026
Silence anomaly: GPT-5.3
GPT-5.3 (ai_model) has 42 total mentions but hasn't appeared in any article for 19 days. Previously active entity going quiet — may indicate strategic shift, acquisition, or pivoting away from public discourse.
70% confidence
Sentiment History
| Week | Avg Sentiment | Mentions |
|---|---|---|
| 2026-W26 | -0.05 | 2 |
| 2026-W30 | -0.20 | 1 |
| 2026-W31 | 0.40 | 1 |