# GPT-5.3 Codex vs Beam 1.0 501B-A23B FP8

> Side-by-side benchmark comparison for GPT-5.3 Codex and Beam 1.0 501B-A23B FP8 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gpt-5-3-codex-vs-reflection-beam-fp8
- Last updated: October 16, 2026

- Shared sourced benchmarks: 2
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Evidence is too thin for a benchmark verdict: GPT-5.3 Codex and Beam 1.0 501B-A23B FP8 share only 2 sourced benchmark rows.

## Summary

- Only 2 shared sourced benchmark rows are available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- Beam 1.0 501B-A23B FP8 has the lower published output-token price.
- Beam 1.0 501B-A23B FP8 has the larger published context window at 1M.

## Model Snapshot

| Property | GPT-5.3 Codex | Beam 1.0 501B-A23B FP8 |
|----------|----------|----------|
| Creator | OpenAI | Reflection AI |
| Type | Proprietary | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 400K | 1M |
| Independent public score (not head-to-head) | 60.47 | null |
| Benchmarks Covered | 11 | 19 |
| Pricing (input/output) | $1.75 / $14.00 | Pricing unavailable / Pricing unavailable |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- GPT-5.3 Codex public-lane score: 55.5 (Estimated · #41/128)
- Beam 1.0 501B-A23B FP8 public-lane score: Coming soon

| Benchmark | GPT-5.3 Codex | Beam 1.0 501B-A23B FP8 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.0 | 77.3% | Coming soon | Coming soon |
| OSWorld-Verified | 64.7% | Coming soon | Coming soon |
| Gert Labs | 57.47% | Coming soon | Coming soon |
| JobBench | 33.7% | Coming soon | Coming soon |
| τ³-bench results | Coming soon | 36.8% | Coming soon |
| HLE w/ tools | Coming soon | 51.1% | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 78.9% | Coming soon |
| MCP Atlas | Coming soon | 81.5% | Coming soon |
| BrowseComp | Coming soon | 76.7% | Coming soon |
| DeepSearchQA | Coming soon | 79.6% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- GPT-5.3 Codex public-lane score: 53.5 (Supported · #35/150)
- Beam 1.0 501B-A23B FP8 public-lane score: Coming soon

| Benchmark | GPT-5.3 Codex | Beam 1.0 501B-A23B FP8 | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 85% | 80.2% | GPT-5.3 Codex |
| SWE-bench Pro | 56.8% | 65.9% | Beam 1.0 501B-A23B FP8 |
| SWE-Rebench | 58.2% | Coming soon | Coming soon |
| Terminal-Bench 2.0 | 77.3% | Coming soon | Coming soon |
| Vibe Code Bench | 61.77% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 87.3% | Coming soon | Coming soon |
| SWE-bench (Vals) | 78.0% | Coming soon | Coming soon |
| DeepSWE | Coming soon | 43.0% | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 78.9% | Coming soon |
| SWE-Atlas Codebase QnA | Coming soon | 32.2% | Coming soon |
| SWE Multilingual | Coming soon | 78.1% | Coming soon |
| SciCode | Coming soon | 48.3% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- GPT-5.3 Codex public-lane score: 83.1 (Unranked · 2 rankable rows)
- Beam 1.0 501B-A23B FP8 public-lane score: 85.8 (Unranked · 3 rankable rows)

| Benchmark | GPT-5.3 Codex | Beam 1.0 501B-A23B FP8 | Winner |
|-----------|-----------|-----------|--------|
| CritPt | Coming soon | 17.4% | Coming soon |
| LongBench v2 | Coming soon | 67.6% | Coming soon |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- GPT-5.3 Codex public-lane score: 80.1 (Unranked · 1 rankable row)
- Beam 1.0 501B-A23B FP8 public-lane score: Coming soon

### Knowledge

- Winner: Insufficient shared evidence
- GPT-5.3 Codex public-lane score: 65.3 (Estimated · #32/184)
- Beam 1.0 501B-A23B FP8 public-lane score: Coming soon

| Benchmark | GPT-5.3 Codex | Beam 1.0 501B-A23B FP8 | Winner |
|-----------|-----------|-----------|--------|
| GPQA-D | Coming soon | 90.3% | Coming soon |
| HLE w/o tools | Coming soon | 36% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- GPT-5.3 Codex public-lane score: 92.6 (#18/148)
- Beam 1.0 501B-A23B FP8 public-lane score: 89.8 (#28/148)

| Benchmark | GPT-5.3 Codex | Beam 1.0 501B-A23B FP8 | Winner |
|-----------|-----------|-----------|--------|
| IFBench | Coming soon | 80.7% | Coming soon |

### Mathematics

- Winner: Insufficient shared evidence
- GPT-5.3 Codex public-lane score: Coming soon
- Beam 1.0 501B-A23B FP8 public-lane score: 87.9 (Unranked · 1 rankable row)

| Benchmark | GPT-5.3 Codex | Beam 1.0 501B-A23B FP8 | Winner |
|-----------|-----------|-----------|--------|
| AIME26 | Coming soon | 98.0% | Coming soon |

## FAQ

### Is there enough evidence to pick between GPT-5.3 Codex and Beam 1.0 501B-A23B FP8?

Not yet. The models share only 2 sourced benchmark rows, so this mirror reports the available measurements and metadata without naming a broad winner.

### What can I compare safely on this page?

Published pricing, context windows, model type, and individual shared benchmark rows are directly comparable. Independent overall scores and non-overlapping benchmark coverage are labeled separately and should not be read as a controlled head-to-head result.

## Related Comparisons

- [GPT-5.3 Codex vs GPT-5.3-Codex-Spark](/compare/gpt-5-3-codex-vs-gpt-5-3-codex-spark)
- [Beam 1.0 501B-A23B FP8 vs GPT-5.3-Codex-Spark](/compare/gpt-5-3-codex-spark-vs-reflection-beam-fp8)
- [GPT-5.3 Codex vs Beam 1.0 501B-A23B](/compare/gpt-5-3-codex-vs-reflection-beam)
- [Beam 1.0 501B-A23B FP8 vs Beam 1.0 501B-A23B](/compare/reflection-beam-vs-reflection-beam-fp8)

## Explore More

- [GPT-5.3 Codex profile](/models/gpt-5-3-codex)
- [Beam 1.0 501B-A23B FP8 profile](/models/reflection-beam-fp8)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)