| Signal | Claude Sonnet 4.5 | Delta | GPT-5.3-Codex |
|---|---|---|---|
Capabilities | 100 | -- | |
Pricing | 15 | +1 | |
Context window size | 95 | +6 | |
Recency | 100 | -- | |
Output Capacity | 80 | -5 | |
| Overall Result | 2 wins | of 5 | 1 wins |
12
days ranked higher
5
days
13
days ranked higher
Anthropic
OpenAI
GPT-5.3-Codex saves you $175.00/month
That's $2100.00/year compared to Claude Sonnet 4.5 at your current usage level of 100K calls/month.
| Metric | Claude Sonnet 4.5 | GPT-5.3-Codex | Winner |
|---|---|---|---|
| Overall Score | 96 | 96 | Claude Sonnet 4.5 |
| Rank | #7 | #8 | Claude Sonnet 4.5 |
| Quality Rank | #7 | #8 | Claude Sonnet 4.5 |
| Adoption Rank | #7 | #8 | Claude Sonnet 4.5 |
| Parameters | -- | -- | -- |
| Context Window | 1000K | 400K | Claude Sonnet 4.5 |
| Pricing | $3.00/$15.00/M | $1.75/$14.00/M | -- |
| Signal Scores | |||
| Capabilities | 100 | 100 | Claude Sonnet 4.5 |
| Pricing | 15 | 14 | Claude Sonnet 4.5 |
| Context window size | 95 | 89 | Claude Sonnet 4.5 |
| Recency | 100 | 100 | Claude Sonnet 4.5 |
| Output Capacity | 80 | 85 | GPT-5.3-Codex |
Our composite score (0–100) combines six weighted signals: benchmark performance (25%), pricing efficiency (25%), context window size (15%), model recency (15%), output capacity (10%), and capability versatility (10%). Here's what the scores mean for these two models:
Scores 96/100 (rank #7), placing it in the top 98% of all 290 models tracked.
Scores 96/100 (rank #8), placing it in the top 98% of all 290 models tracked.
With only a 1-point gap, these models are in the same performance tier. The practical difference in output quality is minimal — your choice should depend on pricing, latency requirements, and specific feature needs.
GPT-5.3-Codex offers 13% better value per quality point. At 1M tokens/day, you'd spend $236.25/month with GPT-5.3-Codex vs $270.00/month with Claude Sonnet 4.5 — a $33.75 monthly difference.
Both models have comparable response speeds. For most applications, the latency difference is negligible.
When latency matters most: Interactive chatbots, IDE code completion, real-time translation, and user-facing applications where response time directly impacts experience. For batch processing, background summarization, or offline analysis, latency is less critical.
Code generation & review
Higher benchmark score (0/100) indicates stronger performance on coding tasks like generating functions, debugging, and refactoring
Customer support chatbot
Faster response time (speed score 0/100) is critical for user-facing chat. GPT-5.3-Codex also offers lower per-token costs for high-volume support
Long document analysis
Larger context window (1000K tokens) can process longer documents, contracts, and research papers in a single pass
Batch data extraction
Lower output pricing ($14.00/M) reduces costs when processing thousands of records daily
Creative writing & content
Higher overall composite score (96/100) correlates with better nuance, coherence, and style in long-form content
Image understanding & OCR
Supports vision input — can analyze screenshots, diagrams, photos, and scanned documents directly
Claude Sonnet 4.5 and GPT-5.3-Codex are extremely close in overall performance (only 0.5999999999999943 points apart). Your best choice depends entirely on which specific strengths matter most for your use case.
Best for Quality
Claude Sonnet 4.5
Marginally better benchmark scores; both are excellent
Best for Cost
GPT-5.3-Codex
13% lower pricing; better value at scale
Best for Reliability
Claude Sonnet 4.5
Higher uptime and faster response speeds
Best for Prototyping
Claude Sonnet 4.5
Stronger community support and better developer experience
Best for Production
Claude Sonnet 4.5
Wider enterprise adoption and proven at scale
by Anthropic
| Capability | Claude Sonnet 4.5 | GPT-5.3-Codex |
|---|---|---|
| Vision (Image Input) | ||
| Function Calling | ||
| Streaming | ||
| JSON Mode | ||
| Reasoning | ||
| Web Search | ||
| Image Output |
Anthropic
OpenAI
GPT-5.3-Codex saves you $3.45/month
That's 15% cheaper than Claude Sonnet 4.5 at 1,000 tokens/request and 100 requests/day.
Assumes 60% input / 40% output token ratio per request. Actual costs may vary based on your usage pattern.
| Parameter | Claude Sonnet 4.5 | GPT-5.3-Codex |
|---|---|---|
| Context Window | 1M | 400K |
| Max Output Tokens | 64,000 | 128,000 |
| Open Source | No | No |
| Created | Sep 29, 2025 | Feb 24, 2026 |
Claude Sonnet 4.5 scores 96/100 (rank #7) compared to GPT-5.3-Codex's 96/100 (rank #8), giving it a 1-point advantage. Claude Sonnet 4.5 is the stronger overall choice, though GPT-5.3-Codex may excel in specific areas like cost efficiency.
Claude Sonnet 4.5 is ranked #7 and GPT-5.3-Codex is ranked #8 out of 290+ AI models. Rankings use a composite score combining benchmark performance (25%), pricing (25%), context window (15%), recency (15%), output capacity (10%), and versatility (10%). Scores update hourly.
GPT-5.3-Codex is cheaper at $14.00/M output tokens vs Claude Sonnet 4.5's $15.00/M output tokens — 1.1x more expensive. Input token pricing: Claude Sonnet 4.5 at $3.00/M vs GPT-5.3-Codex at $1.75/M.
Claude Sonnet 4.5 has a larger context window of 1,000,000 tokens compared to GPT-5.3-Codex's 400,000 tokens. A larger context window means the model can process longer documents and conversations.