claude-sonnet-4-5 vs gpt-5.3-codex
Side-by-side comparison of claude-sonnet-4-5 and gpt-5.3-codex: benchmarks, pricing, context window and capabilities. Both are accessible through Requesty's unified API. gpt-5.3-codex outperforms claude-sonnet-4-5 on 5 of 5 shared benchmarks.
claude-sonnet-4-5
Input / 1M
$3.00
Output / 1M
$15.00
Context
1M
Model ID
anthropic/claude-sonnet-4-5
gpt-5.3-codex
Input / 1M
$1.75
Output / 1M
$14.00
Context
400K
Model ID
openai-responses/gpt-5.3-codex
Benchmark comparison
Intelligence Indexreasoning
claude-sonnet-4-527.3%
gpt-5.3-codex36.9%
Coding Indexcoding
claude-sonnet-4-552.1%
gpt-5.3-codexN/A
Math Indexmath
claude-sonnet-4-588.0%
gpt-5.3-codexN/A
GPQA Diamondreasoning
claude-sonnet-4-583.4%
gpt-5.3-codex91.5%
AIME 2025math
claude-sonnet-4-588.0%
gpt-5.3-codexN/A
LiveCodeBenchcoding
claude-sonnet-4-571.4%
gpt-5.3-codexN/A
Terminal-Bench Hardagentic
claude-sonnet-4-535.6%
gpt-5.3-codex53.0%
τ²-Benchagentic
claude-sonnet-4-578.1%
gpt-5.3-codex86.0%
SciCodecoding
claude-sonnet-4-545.7%
gpt-5.3-codexN/A
MMLU Proknowledge
claude-sonnet-4-587.5%
gpt-5.3-codexN/A
Humanity's Last Examreasoning
claude-sonnet-4-517.8%
gpt-5.3-codex42.5%
Scores sourced from official model cards, Artificial Analysis, and public leaderboards. Benchmarks measure specific skills and don't capture every aspect of model quality.
Pricing & specifications
| claude-sonnet-4-5 | gpt-5.3-codex | |
|---|---|---|
| Input price / 1M | $3.00 | $1.75 |
| Output price / 1M | $15.00 | $14.00 |
| Context window | 1M tokens | 400K tokens |
| Max output | 64K tokens | 128K tokens |
| Vision input | Yes | Yes |
| Tool calling | Yes | Yes |
| Reasoning | Yes | Yes |
| Prompt caching | Yes | Yes |
| Computer use | Yes | N/A |
| Provider | Anthropic PBC | OpenAI Responses |
Questions people ask
Is claude-sonnet-4-5 better than gpt-5.3-codex?
gpt-5.3-codex outperforms claude-sonnet-4-5 on 5 of 5 shared benchmarks. See the benchmark comparison above for specifics: claude-sonnet-4-5 and gpt-5.3-codex have different strengths across reasoning, coding, math and multimodal tasks.
Which is cheaper, claude-sonnet-4-5 or gpt-5.3-codex?
gpt-5.3-codex is cheaper. claude-sonnet-4-5 costs $3.00/$15.00 per 1M input/output tokens, while gpt-5.3-codex costs $1.75/$14.00.
Can I use claude-sonnet-4-5 and gpt-5.3-codex through the same API?
Yes. Requesty provides a single OpenAI-compatible API that routes to both. Change just the "model" parameter to switch between "anthropic/claude-sonnet-4-5" and "openai-responses/gpt-5.3-codex", no other code changes needed.
What are the context windows?
claude-sonnet-4-5 supports up to 1M tokens of context. gpt-5.3-codex supports up to 400K tokens. Longer context means you can feed larger documents or codebases in a single prompt, though quality often degrades past 128K for most models.
Switch between claude-sonnet-4-5 and gpt-5.3-codex with one line of code
Requesty provides a single OpenAI-compatible API for 600+ models. Change the model parameter, not your code.