whatmodel.sh / UL2 20B

UL2 20B is an open-weights language model from Google, released May 2022. Its published size is 20B parameters. Licence: apache-2.0.

Catalogue identity notes

Google UL2 20B encoder-decoder pretrained with mixture-of-denoisers (not Flan-UL2, released 2023-02). Recitation paper Table 7 lists 19.46B parameters. arXiv:2205.05131v1 (submitted 10 May 2022) abstract: 'We release Flax-based T5X model checkpoints for the 20B model at https://github.com/google-research/google-research/tree/master/ul2.' Hugging Face google/ul2 (Apache-2.0) first commit 2022-06-16.

Model information sources

Release date ↗

28.0±2.6comparison only: no current run option verifiedfrom 4 benchmark results across 2 sources

Score within the LMArena (text) comparison set only.

$ how it compares

The LLMs ranked either side of UL2 20B, out of 877 with a score, then more from Google.

#modelscorewhereRAMreleased
799Granite 4.0 350M IBM28±1local~1.7GB2025-10
800OPT-30B Meta28±1local~64GB2022-05
801UL2 20B Google28±3comparison only2022-05
802GPT-NeoX-20B EleutherAI28±1local~14GB2022-02
803Qwen2 0.5B Instruct Alibaba28±2local~1GB2024-06
more from Google
11Gemini 4 Argon Google80±1api $4.00/M2026-09
26Gemini 3.8 Flash Google76±1api $1.50/M2026-09
34Gemini 3.7 Flash Google75±1api $1.50/M2026-08

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$ what it's good at

mathnot ranked on this task yet · 1 test
testresultvs the others in its rundifficultycountswhy
GSM8K lab5.4% ✎▂▂▂▃▃▄▅▇██▆▄ beats 27/200easy · avg 72%—not counted yet: no other model in the same run to compare it with
other tests5 not in a task · 97% of its score
testresultvs the others in its rundifficultycountswhy
ARC Challenge lab +142.9% ✎▄▁▁▂▁▄█▇▃▂▃▂ beats 86/140easy · avg 86%▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ 56%sharp
TriviaQA lab48.7% ✎▁▁▂▂▄▄▃▆▅█▅▂ beats 45/80easy · avg 80%▇▇▇▇▇▇▇▇ 20%at its level · small run
Natural Questions (closed book) lab10.2% ✎▂▁▁▁▂▄▄▃▅█▅▁ beats 27/68medium · avg 38%▇▇▇▇▇▇ 14%small run
ARC Easy lab61.6% ✎▁▃▂▄▆█▅▃▁··▁ beats 35/100easy · avg 87%▇▇▇ 6.5%blunt · at its level
OpenBookQA lab53.6% ✎▅▁▁▁▂▂▃█▃▁▃▁ beats 83/107hard · avg 48%—not counted yet: no other model in the same run to compare it with

$ where to run it

No verified API or download recorded yet · add one

Official weights and documentation: huggingface.co/google ↗

$ how the score was worked out · Self-Consistency Improves Cha… 62%, Recitation-Augmented Language… 35%

Each result implies a score on its own, after adjusting for how hard its test is and who ran it. The score is their weighted average, with a small pull toward the middle for thinly tested models. Each test's weight is its counts column above; here it's added up by who ran the tests. How it works

sourceresultsshare of the scorelicence
Self-Consistency Improves Chain of Thought Reasoning in Language Models — authors' own runs · lab-reported2CC BY 4.0
Recitation-Augmented Language Models — authors' own runs · lab-reported2CC BY 4.0
prior · pull toward the middle
weighted average= 28.0

not counted (3)

Large Language Models Can Self-Improve — authors' own runsGSM8K [correct]5.4%fewer than three models have this test yet, or this source ran it for this model alone
Large Language Models Can Self-Improve — authors' own runsARC Challenge [correct]49.9%the only model in this source's run of the test, so there is nothing to compare it with there; another run of the test counts
Large Language Models Can Self-Improve — authors' own runsOpenBookQA [correct]53.6%fewer than three models have this test yet, or this source ran it for this model alone

$ improve this page

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data updated · sources and licences · json