What are the best alternatives to c4?

The top alternatives to c4 are Hugging Face MCP Server, Langfuse, The Stack v2, ranked by real usage data on Unfragile.

Are there free alternatives to c4?

Yes, 20 free alternatives to c4 exist, including Hugging Face MCP Server, Langfuse, The Stack v2.

Best c4 Alternatives (2026) — Ranked by Real Data | Unfragile

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Best Alternatives to c4

20 alternatives ranked by real usage data. c4 scores 21/100 — 20 tools score higher.

Originalc4

Dataset by allenai. 7,61,810 downloads.

20 alternatives

20 free options

20 score higher

Hugging Face MCP Server82/100FreeHigher rated

Official Hugging Face MCP — search models/datasets/Spaces/papers and call Spaces as tools.

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Langfuse62/100FreeHigher rated

Open-source LLM observability — tracing, prompt management, evaluation, cost tracking, self-hosted.

Repository

The Stack v261/100FreeHigher rated

67 TB permissively licensed code dataset across 600+ languages.

Dataset

The Pile61/100FreeHigher rated

EleutherAI's 825 GiB diverse training dataset from 22 sources.

Dataset

RedPajama v261/100FreeHigher rated

30 trillion token web dataset with 40+ quality signals per document.

Dataset

Polyaxon61/100FreeHigher rated

ML lifecycle platform with distributed training on K8s.

Platform

MS COCO (Common Objects in Context)61/100FreeHigher rated

330K images with object detection, segmentation, and captions.

Dataset

MLflow61/100FreeHigher rated

Open-source ML lifecycle platform — experiment tracking, model registry, serving, LLM tracing.

Repository

LAION-5B61/100FreeHigher rated

5.85 billion image-text pairs foundational for image generation.

Dataset

Hugging Face61/100FreeHigher rated

The GitHub for AI — 500K+ models, datasets, Spaces, Inference API, hub for open-source AI.

Platform

Featureform61/100FreeHigher rated

Virtual feature store on existing data infrastructure.

Platform

Determined AI61/100FreeHigher rated

Deep learning training platform — distributed training, hyperparameter search, GPU scheduling.

Repository

CulturaX61/100FreeHigher rated

6.3T token multilingual dataset across 167 languages.

Dataset

ClearML61/100FreeHigher rated

Open-source MLOps — experiment tracking, pipelines, data management, auto-logging, self-hosted.

Repository

Argilla61/100FreeHigher rated

Open-source data curation for LLM fine-tuning and RLHF.

Repository

TriviaQA60/100FreeHigher rated

95K trivia questions requiring cross-document reasoning.

Dataset

ToxiGen60/100FreeHigher rated

Microsoft's dataset for implicit toxicity detection.

Dataset

Supervisely60/100FreeHigher rated

Enterprise computer vision platform for teams.

Platform

StarCoderData60/100FreeHigher rated

250GB curated code dataset for StarCoder training.

Dataset

StarCoder Data60/100FreeHigher rated

783 GB curated code dataset from 86 languages with PII redaction.

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