---
language:
  - ta
license: cc-by-sa-4.0
task_categories:
  - text-generation
  - fill-mask
tags:
  - tamil
  - corpus
  - nlp
  - llm-training
  - indic
  - dravidian
pretty_name: "mozhi-ai Tamil Corpus"
size_categories:
  - 1K<n<10K
---

# mozhi-ai Tamil Corpus

A continuously-updated, high-quality Tamil language corpus for LLM training.
Collects text from classical literature, Wikipedia, news, and web sources.

## Corpus Stats (updated 2026-05-30)

| Metric | Value |
|--------|-------|
| **Total Documents** | 8,682 |
| **Total Characters** | 4,961,439 |
| **Total Words** | 554,078 |
| **Deduplicated** | 0 removed |
| **Quality Filtered** | 0 removed |
| **Last Updated** | 2026-05-30 |

### Sources Breakdown

| Source | Documents |
|--------|-----------|
| hf:ai4bharat/IndicCorpV2 | 8,155 |
| wikipedia | 488 |
| project_madurai | 39 |

### Licenses

| License | Documents |
|---------|-----------|
| CC-0 | 8,155 |
| CC-BY-SA-4.0 | 488 |
| public-domain | 39 |

### Domains

| Domain | Documents |
|--------|-----------|
| news | 8,155 |
| encyclopedia | 488 |
| classical_literature | 39 |

### Registers

| Register | Documents |
|----------|-----------|
| formal | 8,643 |
| classical | 39 |

## Data Fields

| Field | Type | Description |
|-------|------|-------------|
| `id` | string | Unique document ID (SHA-256 content hash) |
| `text` | string | The Tamil text content |
| `source` | string | Data source identifier |
| `url` | string | Source URL (when available) |
| `license` | string | License of the source data |
| `date_collected` | string | Collection date (ISO 8601) |
| `domain` | string | Content domain: `news`, `encyclopedia`, `classical_literature`, `web` |
| `register` | string | Language register: `classical`, `formal`, `colloquial` |
| `title` | string | Document title (Wikipedia, Madurai) |
| `language_score` | float | fastText Tamil confidence (0-1) |
| `quality_score` | float | Quality heuristic score (0-1) |
| `tamil_char_ratio` | float | Ratio of Tamil script chars to total non-whitespace |
| `unique_word_ratio` | float | Ratio of unique words to total words |
| `avg_word_length` | float | Average characters per word |
| `word_count` | int | Total word count |
| `char_count` | int | Total character count |
| `sentence_count` | int | Sentence count (based on punctuation) |
| `pii_count` | int | Detected PII instances (emails, phones, IPs) |
| `has_code_switching` | bool | Contains significant English (Tanglish) |

## Processing Pipeline

Every document passes through:

1. **Language Detection** — fastText `lid.176.bin` (threshold: 0.7)
2. **Unicode Normalization** — NFKC + Tamil-specific normalization (indic_nlp_library)
3. **Exact Deduplication** — SHA-256 content hashing
4. **Quality Filtering** — length, Tamil character ratio, uniqueness, boilerplate detection
5. **Annotation** — domain, register, text stats, PII detection, code-switching

## Sources

- **IndicCorpV2** (AI4Bharat) — Tamil news and articles (CC-0)
- **allenai/c4** — Web-crawled Tamil text (ODC-BY)
- **Tamil Wikipedia** — Encyclopedia articles (CC-BY-SA-4.0)
- **Project Madurai** — Classical Tamil literature (Public Domain)

## Usage

```python
from datasets import load_dataset

# Load the full dataset
ds = load_dataset("mozhi-ai/tamil-corpus")

# Stream without downloading
ds = load_dataset("mozhi-ai/tamil-corpus", streaming=True)

# Access the text
for example in ds["train"]:
    print(example["text"][:100])
```

## Citation

If you use this corpus, please cite:

```bibtex
@misc{mozhi-ai-tamil-corpus,
  title={mozhi-ai Tamil Corpus},
  author={mozhi-ai contributors},
  year={2026},
  url={https://huggingface.co/datasets/mozhi-ai/tamil-corpus}
}
```

## Contributing

This is an open project. Contributions welcome at [GitHub](https://github.com/mozhi-ai).

---

*Built with [mozhi-ai](https://github.com/mozhi-ai) — automated Tamil corpus pipeline*