--- title: "lightly vs pytorch-lightning" type: "comparison" canonical_url: "https://www.graphcanon.com/compare/lightly-ai-lightly-vs-lightning-ai-pytorch-lightning" tools: ["lightly-ai-lightly", "lightning-ai-pytorch-lightning"] --- # lightly vs pytorch-lightning *GraphCanon updated Jul 12, 2026* ## Verdict Pick lightly when license: lightly is MIT, pytorch-lightning is Apache-2.0; pick pytorch-lightning when license: pytorch-lightning is Apache-2.0, lightly is MIT. [lightly](https://docs.lightly.ai/self-supervised-learning/) reports 3.8k GitHub stars, 339 forks, and 92 open issues, last pushed Jul 9, 2026. [pytorch-lightning](https://lightning.ai/pytorch-lightning/?utm_source=ptl_readme&utm_medium=referral&utm_campaign=ptl_readme) has 31k stars, 3.8k forks, and 1.0k open issues, last pushed Jul 10, 2026. Figures are from public GitHub metadata via [lightly's repository](https://github.com/lightly-ai/lightly) and [pytorch-lightning's repository](https://github.com/Lightning-AI/pytorch-lightning). | | [lightly](/tools/lightly-ai-lightly.md) | [pytorch-lightning](/tools/lightning-ai-pytorch-lightning.md) | | --- | --- | --- | | Tagline | A python library for self-supervised learning on images | Pretrain, finetune ANY AI model of ANY size on 1 or 10,000+ GPUs with zero code changes. | | Stars | 3,777 | 31,233 | | Forks | 339 | 3,756 | | Open issues | 92 | 1,049 | | Language | Python | Python | | Adopt for | - | - | | Persona | - | - | | Runtime | - | - | | License | MIT | Apache-2.0 | | Categories | Computer Vision, Model Training | Computer Vision, Model Training | ## Trust and health _Sourced signals - not a safety guarantee. No winner column._ | | [lightly](/tools/lightly-ai-lightly.md) | [pytorch-lightning](/tools/lightning-ai-pytorch-lightning.md) | | --- | --- | --- | | Open issues (now) | 92 | 1.0k | | Security scan | No lockfile | No criticals | | Full report | [trust report](/tools/lightly-ai-lightly/trust.md) | [trust report](/tools/lightning-ai-pytorch-lightning/trust.md) | ## Choose when ### Choose lightly if… - License: lightly is MIT, pytorch-lightning is Apache-2.0. - Tags unique to lightly: computer-vision, contrastive-learning, embeddings, self-supervised-learning. - Leaner open-issue backlog (92). ### Choose pytorch-lightning if… - License: pytorch-lightning is Apache-2.0, lightly is MIT. - Tags unique to pytorch-lightning: ai, artificial-intelligence, data-science, machine-learning. - More GitHub stars (31k vs 3.8k) - visibility, not fit. ## When NOT to use lightly - Model Training: Try prompting and RAG first; fine-tuning is the answer to style/format, not missing knowledge. ## When NOT to use pytorch-lightning - Model Training: Try prompting and RAG first; fine-tuning is the answer to style/format, not missing knowledge. ## Common questions ### What is the difference between lightly and pytorch-lightning? lightly: A python library for self-supervised learning on images. pytorch-lightning: Pretrain, finetune ANY AI model of ANY size on 1 or 10,000+ GPUs with zero code changes.. See the comparison table for live GitHub stats and shared categories. ### When should I choose lightly over pytorch-lightning? Choose lightly over pytorch-lightning when License: lightly is MIT, pytorch-lightning is Apache-2.0; Tags unique to lightly: computer-vision, contrastive-learning, embeddings, self-supervised-learning; Leaner open-issue backlog (92). ### When should I choose pytorch-lightning over lightly? Choose pytorch-lightning over lightly when License: pytorch-lightning is Apache-2.0, lightly is MIT; Tags unique to pytorch-lightning: ai, artificial-intelligence, data-science, machine-learning; More GitHub stars (31k vs 3.8k) - visibility, not fit. ### When should I avoid lightly? Model Training: Try prompting and RAG first; fine-tuning is the answer to style/format, not missing knowledge. ### When should I avoid pytorch-lightning? Model Training: Try prompting and RAG first; fine-tuning is the answer to style/format, not missing knowledge. ### Is lightly or pytorch-lightning more popular on GitHub? pytorch-lightning has more GitHub stars (31,233 vs 3,777). Stars measure visibility, not whether either tool fits your constraints. ### Are lightly and pytorch-lightning open source? Yes - both are open-source projects on GitHub (lightly: MIT, pytorch-lightning: Apache-2.0). ### Where can I find alternatives to lightly or pytorch-lightning? GraphCanon lists graph-backed alternatives at [lightly alternatives](/tools/lightly-ai-lightly/alternatives) and [pytorch-lightning alternatives](/tools/lightning-ai-pytorch-lightning/alternatives) ([lightly markdown twin](/tools/lightly-ai-lightly/alternatives.md), [pytorch-lightning markdown twin](/tools/lightning-ai-pytorch-lightning/alternatives.md)), ranked by typed relationship edges rather than popularity votes. ### Is there a machine-readable version of this comparison? Yes. The markdown twin at [this comparison](/compare/lightly-ai-lightly-vs-lightning-ai-pytorch-lightning.md) mirrors this page for agents and LLM crawlers, with the same stats table and FAQ answers. ### Which is better maintained, lightly or pytorch-lightning? lightly: Very active. pytorch-lightning: Very active. Compare maintenance labels, days since push, and release cadence in the trust section below - stars alone do not measure maintenance. ### Where are the full trust reports for lightly and pytorch-lightning? GraphCanon publishes per-repo trust reports with dated maintenance, provenance, and scan summaries: [lightly trust report](/tools/lightly-ai-lightly/trust); [pytorch-lightning trust report](/tools/lightning-ai-pytorch-lightning/trust). --- **Machine-readable endpoints** - JSON: [`/api/graphcanon/graph?tool=lightly-ai-lightly`](/api/graphcanon/graph?tool=lightly-ai-lightly) - LLM index: [/llms.txt](/llms.txt) - Full corpus: [/llms-full.txt](/llms-full.txt) _GraphCanon - The knowledge graph for AI development. https://www.graphcanon.com/_