# specter2_base by Ai2: Open-Weight Model
Source: https://savrn.com/models/specter2-base
Markdown alternate of the page above; the site index is https://savrn.com/llms.txt

---

## Model Card

By Ai2, published under apache-2.0, revision 3447645e1def.

### SPECTER2

SPECTER2 is the successor to [SPECTER](https://huggingface.co/allenai/specter) and is capable of generating task specific embeddings for scientific tasks when paired with [adapters](https://huggingface.co/models?search=allenai/specter-2_). This is the base model to be used along with the adapters. Given the combination of title and abstract of a scientific paper or a short texual query, the model can be used to generate effective embeddings to be used in downstream applications.

Note:For general embedding purposes, please use [allenai/specter2](https://huggingface.co/allenai/specter2).

To get the best performance on a downstream task type please load the associated adapter with the base model as in the example below.

Dec 2023 Update:

Model usage updated to be compatible with latest versions of transformers and adapters (newly released update to adapter-transformers) libraries.

Aug 2023 Update: 1. The SPECTER2 Base and proximity adapter models have been renamed in Hugging Face based upon usage patterns as follows:

| Old Name | New Name |
| --- | --- |
| allenai/specter2 | [allenai/specter2_base](https://savrn.com/models/specter2-base) |
| allenai/specter2_proximity | [allenai/specter2](https://huggingface.co/allenai/specter2) |

[Read the full model card (883 words)](https://savrn.com/models/specter2-base/card)

## Configuration

Architecture

BertModel

Context length (tokens)

512

Layers

12

Hidden size

768

Feed-forward size

3,072

Attention heads

12

Vocabulary size

31,090

Stored precision

float32

Model type

bert

## Identity and Version

Repository

allenai/specter2_base

Publisher

Ai2

Task

Feature extraction

Modality

Text

Library

transformers

Parameters

Not stated by the source

Languages

en

Revision

3447645e1def9117997203454fa4495937bfbd83

First published

2023-02-16

Last updated

2024-12-04

## Files and Weights

8 files, 440.7 MB in total. The weights are 1 file totalling 439.7 MB in bin.

Weights1 file · 439.7 MB

Configuration2 files · 879 B

Tokenizer3 files · 945.1 KB

Documentation1 file · 9.2 KB

Repository1 file · 1.5 KB

Every file

| File | Type | Size | SHA-256 |
| --- | --- | --- | --- |
| pytorch_model.bin | Weights | 439.7 MB | 801eda968fad |
| config.json | Configuration | 754 B | — |
| special_tokens_map.json | Configuration | 125 B | — |
| README.md | Documentation | 9.2 KB | — |
| .gitattributes | Repository | 1.5 KB | — |
| tokenizer.json | Tokenizer | 716.8 KB | — |
| tokenizer_config.json | Tokenizer | 453 B | — |
| vocab.txt | Tokenizer | 227.8 KB | — |

## License and Download

License

apache-2.0

Access

Open weights, no gate

Download size

439.7 MB

[Download from Ai2](https://huggingface.co/allenai/specter2_base)

Released by Ai2 through its official repository on Hugging Face. [Read the license](https://www.apache.org/licenses/LICENSE-2.0).

## Built From

- Trained on (disclosed) allenai/scirepeval

## Memory Requirements

| Precision | Weights in memory |
| --- | --- |
| As published | 439.7 MB |

Weights only, from the published parameter count; the key-value cache and runtime add to this.

## Questions About specter2_base

### Can I use specter2_base commercially?

Yes. specter2_base is released under Apache License 2.0. The Apache License 2.0 is a permissive open-source license. It permits commercial use, modification and redistribution. It requires keeping the license and copyright notices and any NOTICE file, stating significant changes, and it includes an express patent grant from contributors.

### What is specter2_base's context length?

512 tokens, from the maximum position embeddings in its published configuration.

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## Ai2

[All models and datasets](https://savrn.com/model-publishers/allenai)

## Versions

- [3447645e1def](https://savrn.com/models/specter2-base/versions/3447645e1def) · current 2026-10-12

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## Source

- Repository metadata, read 2026-10-19.
- [Ai2 website](https://allenai.org/)
- [Hugging Face record](https://huggingface.co/allenai/specter2_base)
- [How the hub is built](https://savrn.com/model-hub/methodology)
