1-bit Bonsai 4B vs GPT-5.3 Codex

Side-by-side benchmark comparison across agentic, coding, multimodal, knowledge, reasoning, and math workflows.

Agentic
Coding
Multimodal & Grounded
Reasoning
Knowledge
Instruction Following
Multilingual
Mathematics

1-bit Bonsai 4B· GPT-5.3 Codex

Quick Verdict

Pick GPT-5.3 Codex if you want the stronger benchmark profile. 1-bit Bonsai 4B only becomes the better choice if you want the cheaper token bill or you would rather avoid the extra latency and token burn of a reasoning model.

GPT-5.3 Codex is clearly ahead on the aggregate, 85 to 44. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

GPT-5.3 Codex's sharpest advantage is in reasoning, where it averages 92.5 against 41.4. The single biggest benchmark swing on the page is MATH-500, 65.8% to 99%.

GPT-5.3 Codex is also the more expensive model on tokens at $2.50 input / $10.00 output per 1M tokens, versus $0.00 input / $0.00 output per 1M tokens for 1-bit Bonsai 4B. That is roughly Infinityx on output cost alone. GPT-5.3 Codex is the reasoning model in the pair, while 1-bit Bonsai 4B is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. GPT-5.3 Codex gives you the larger context window at 400K, compared with 32K for 1-bit Bonsai 4B.

Operational tradeoffs

PriceFree*$2.50 / $10.00
SpeedN/A79 t/s
TTFTN/A88.26s
Context32K400K

Decision framing

BenchLM keeps the benchmark table and the operator tradeoffs on the same page so a better score does not hide a materially slower, pricier, or smaller-context model.

Runtime metrics show N/A when BenchLM does not have a sourced snapshot for that exact model. The scoring rules and freshness policy are documented on the methodology page.

Benchmark1-bit Bonsai 4BGPT-5.3 Codex
Agentic
Terminal-Bench 2.077.3%
BrowseComp88%
OSWorld-Verified64.7%
Coding
SWE-bench Verified85%
LiveCodeBench85%
SWE-bench Pro56.8%
SWE-Rebench58.2%
React Native Evals80.9%
Multimodal & Grounded
MMMU-Pro89%
OfficeQA Pro94%
ReasoningGPT-5.3 Codex wins
MuSR41.4%
BBH98%
LongBench v292%
MRCRv293%
KnowledgeGPT-5.3 Codex wins
GPQA28.7%
MMLU-Pro90%
HLE44%
FrontierScience90%
SimpleQA95%
Instruction FollowingGPT-5.3 Codex wins
IFEval69.6%93%
Multilingual
MGSM96%
MMLU-ProX91%
MathematicsGPT-5.3 Codex wins
MATH-50065.8%99%
AIME 202399%
AIME 202499%
AIME 202598%
HMMT Feb 202395%
HMMT Feb 202497%
HMMT Feb 202596%
BRUMO 202596%
Frequently Asked Questions (5)

Which is better, 1-bit Bonsai 4B or GPT-5.3 Codex?

GPT-5.3 Codex is ahead overall, 85 to 44. The biggest single separator in this matchup is MATH-500, where the scores are 65.8% and 99%.

Which is better for knowledge tasks, 1-bit Bonsai 4B or GPT-5.3 Codex?

GPT-5.3 Codex has the edge for knowledge tasks in this comparison, averaging 76.9 versus 28.7. 1-bit Bonsai 4B stays close enough that the answer can still flip depending on your workload.

Which is better for math, 1-bit Bonsai 4B or GPT-5.3 Codex?

GPT-5.3 Codex has the edge for math in this comparison, averaging 97.6 versus 65.8. Inside this category, MATH-500 is the benchmark that creates the most daylight between them.

Which is better for reasoning, 1-bit Bonsai 4B or GPT-5.3 Codex?

GPT-5.3 Codex has the edge for reasoning in this comparison, averaging 92.5 versus 41.4. 1-bit Bonsai 4B stays close enough that the answer can still flip depending on your workload.

Which is better for instruction following, 1-bit Bonsai 4B or GPT-5.3 Codex?

GPT-5.3 Codex has the edge for instruction following in this comparison, averaging 93 versus 69.6. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Last updated: March 31, 2026

Weekly LLM Benchmark Digest

Get notified when new models drop, benchmark scores change, or the leaderboard shifts. One email per week.

Free. No spam. Unsubscribe anytime. We only store derived location metadata for consent routing.