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Open-source deep learning courses, software, and research for coders

fast.ai is an open-source deep learning education platform for software developers learning practical AI and neural networks.

AI Panel Score

8.2/10

6 AI reviews

Reviewed

AI Editor Approved

What is Fast.ai?

Fast.ai is an open-source deep learning education platform for software developers learning practical AI and neural networks. It provides free courses, including the flagship Practical Deep Learning for Coders, alongside the fastai Python library built on PyTorch and the nbdev notebook-driven development tool. Courses are structured around hands-on coding first, introducing theory progressively rather than as a prerequisite, and the accompanying book extends the same curriculum. The entire catalog is free to use, with no paid tiers. Other components include the From Deep Learning Foundations to Stable Diffusion course, an applied data ethics course, the fastchan conda distribution, and the newer Solveit platform. TopReviewed's six-seat AI review panel scored it 8.2/10, praising the layered fastai API that keeps full PyTorch access available while noting the absence of completion certificates limits its use as a hiring signal. It best fits working developers who want production-grade PyTorch depth without a paywall.

About Fast.ai

fast.ai's primary offering is a set of free online courses, most notably 'Practical Deep Learning for Coders' and the newer 'How To Solve It With Code.' These courses are structured so that learners begin writing working models immediately, using real datasets, before diving into underlying theory. Course materials include video lectures, Jupyter notebooks, and accompanying written content.

The fastai library, built on top of PyTorch, provides a layered API that exposes high-level components for common deep learning tasks while allowing access to lower-level PyTorch primitives when needed. The project also maintains nbdev, a tool that enables software development directly inside Jupyter notebooks with full support for testing, documentation generation, and git-compatible version control. A companion textbook, 'Practical Deep Learning for Coders with fastai and PyTorch,' was published through O'Reilly and covers the same curriculum as the course.

fast.ai courses and software are aimed at working software developers and data practitioners who have coding experience but limited prior exposure to machine learning. All core courses and libraries are free. The Solveit platform, announced in late 2024 as part of fast.ai joining Answer.AI, is a separate interactive coding environment with its own feature set. Comparable open-source deep learning frameworks include PyTorch Lightning and Keras; comparable course platforms include Coursera's deeplearning.ai and Hugging Face courses.

The fastai library and nbdev are open-source and available on GitHub. The library targets Python environments and integrates directly with PyTorch. Courses are delivered via the web and use Jupyter notebooks, which can be run locally or on cloud platforms such as Google Colab and Kaggle Kernels.

Features

Core

  • Applied Data Ethics Course

    A free online course covering disinformation, bias and fairness, ethical foundations, practical tools, privacy and surveillance, and algorithmic colonialism for those working in tech.

  • From Deep Learning Foundations to Stable Diffusion

    A course offering over 30 hours of video content covering deep learning foundations through advanced topics including Stable Diffusion, released as Practical Deep Learning for Coders Part 2.

  • How to Solve it With Code

    A new course and educational platform from fast.ai (via Answer.AI) designed to make exploration and iterative development easier and faster through code-based problem solving.

  • Practical Deep Learning for Coders

    A free course teaching deep learning through hands-on coding first, with theory introduced progressively, including a complete from-scratch rewrite covering modern deep learning techniques.

  • Solveit Platform

    An educational platform with specific features designed to support exploration and iterative development, integrated with fast.ai's 'How to Solve it With Code' course.

  • fastai Library for PyTorch

    A deep learning Python library built on PyTorch that provides a layered API with high-level components enabling practitioners to quickly achieve state-of-the-art results in standard deep learning tasks.

  • fastdownload

    A Python library that makes it easy for users to download, verify, and extract archives, serving as a utility component within the fastai ecosystem.

  • fasttransform

    A Python library that makes data transformations reversible and extensible through the power of multiple dispatch, enabling reversible pipelines in data science workflows.

  • nbdev Notebook-Driven Development

    A tool that enables software development directly within Jupyter notebooks, solving the Jupyter+git conflict problem and integrating with Quarto for documentation and productivity.

Integration

  • fastchan Conda Mini-Distribution

    A conda mini-distribution focused on the PyTorch ecosystem that simplifies installation and updates of libraries such as PyTorch and related packages.

Support

  • Practical Deep Learning for Coders Book

    A 600-page book co-authored with O'Reilly covering deep learning with fastai and PyTorch, providing a companion reference to the free online courses.

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Pricing Plans

Popular

Free

Free

Anyone with basic coding experience who wants to learn deep learning and AI. Fast.ai is a non-profit research group whose entire course catalog, software libraries, and community resources are provided at no cost.

  • Practical Deep Learning for Coders (full video course)
  • Free open-source fastai library built on PyTorch
  • AI ethics course (with USF Data Institute)
  • Access to forums.fast.ai community
  • Jupyter notebooks, pretrained models, and example datasets
  • No certificate granted for online completion (in-person USF students only)

AI Panel Reviews

The Decision Maker

The Decision Maker

Strategic bet, vendor viability, timing, adoption approval
8.2/10

Free, proven, and shipping — the rare education bet that pays back fast.

fast.ai is a non-profit deep learning education platform built by Jeremy Howard and Rachel Thomas. Courses, the fastai PyTorch library, and nbdev are all free and actively maintained.

Non-profit structure with O'Reilly book distribution, GitHub open-source libraries, and a 2024 merger into Answer.AI. That's a credible 36-month bet. No runway risk when there's no burn rate.

The tradeoff versus deeplearning.ai or Hugging Face courses: fast.ai skips certificates entirely. No credential for online completions. That's a hiring pipeline gap if you're using course completion as a proxy for readiness. But the coding-first structure means engineers ship working models before the theory lecture even starts — that's faster developer ramp than most alternatives.

Nbdev solving the Jupyter-git conflict problem is underrated. If your ML team lives in notebooks, that alone justifies adoption. Pilot this with three to five engineers on the Practical Deep Learning course. You won't need board approval for a $0 line item.

Competitive Positioning7.5

Peers using Coursera's deeplearning.ai get certificates; fast.ai gets faster practical ramp but no credential — depends on what your hiring signal needs.

Reputation Risk9.0

Jeremy Howard co-founded the platform; O'Reilly published the companion book — this is a respected name in the ML community, not a risk.

Speed to Value8.5

Coding-first course structure means engineers run real models on real datasets in the first session, not week four.

Strategic Fit8.5

Directly advances ML capability in engineering teams without displacing existing tooling — fastai sits on top of PyTorch, not beside it.

Vendor Viability7.8

Non-profit with open-source libraries and Answer.AI backing as of 2024 — low failure risk, though roadmap velocity depends on a small founding team.

Pros

  • Entire catalog is free — $0 licensing risk
  • Practical Deep Learning for Coders starts with working models, not prerequisites
  • nbdev resolves the Jupyter-git conflict problem directly
  • fastai library provides layered PyTorch API, accessible without replatforming

Cons

  • No completion certificates for online learners — limits hiring signal use
  • Small core team means roadmap depends on a few key people
  • Solveit platform announced late 2024 — maturity unknown
  • No API or changelog visibility makes it hard to track what's actively maintained

Right for

Engineering teams who want working ML practitioners faster than a theory-first curriculum delivers.

Avoid if

Your L&D program requires certified completions for compliance or hiring purposes.

The Domain Strategist

The Domain Strategist

Craft and strategy in the product's domain — adapts identity per category, same lens
8.2/10

The best free on-ramp to production PyTorch for developers who learn by doing.

fast.ai's layered API and top-down pedagogy have trained more working practitioners than any comparable free resource. The strategic bet here isn't on the platform—it's on the PyTorch ecosystem it deepens.

The fastai library's layered API is the real artifact worth evaluating. High-level abstractions for vision, text, and tabular tasks sit on top of raw PyTorch primitives, which means your team isn't locked into fastai's opinions—they can drop down when they need to. That's the right architecture for a training library. Comparable options like PyTorch Lightning take a similar philosophy but with a more enterprise-facing surface; fastai stays closer to the research-to-production seam.

nbdev is underrated. Solving the Jupyter-git conflict problem is a genuine quality-of-life win for teams where notebooks are first-class artifacts, not just scratchpads. The 30-plus hours in the Stable Diffusion course signals serious curriculum depth, not a surface-level intro.

The tradeoff is organizational: fast.ai is built for individual learners, not team onboarding pipelines. No certification, no admin tooling, no cohort management. If you're running structured upskilling across a data science org, you'll need to wrap this in your own LMS. For self-directed practitioners, that's irrelevant.

Category Positioning8.4

Free, PyTorch-native, and practitioner-focused puts it clearly above deeplearning.ai's paywalled Coursera tracks for cost-conscious engineering orgs.

Domain Fit8.0

Top-down coding-first structure matches how experienced developers actually learn fastest, but lacks team-level workflow tooling senior practitioners need.

Integration Surface7.8

Native PyTorch compatibility and Colab/Kaggle support cover most practitioner stacks; no enterprise SSO or LMS integration documented.

Long-term Implications8.2

Betting on PyTorch is a safe three-year call; the Answer.AI acquisition adds Solveit as an evolving platform surface worth watching.

Strategic Depth8.5

Layered PyTorch API with reversible transform pipelines via fasttransform shows library-grade thinking, not tutorial scaffolding.

Pros

  • Layered fastai API lets practitioners work high-level without losing PyTorch access
  • nbdev resolves the Jupyter-git conflict problem that quietly kills notebook-based workflows
  • 30-plus hours of curriculum through Stable Diffusion signals genuine depth
  • Entirely free—no seat cost, no trial gates

Cons

  • No certification or admin tooling makes org-wide upskilling programs hard to manage
  • Solveit platform details are thin; Answer.AI integration trajectory is still unclear
  • No changelog or API versioning surface documented publicly, which matters for library dependents

Right for

Self-directed engineers and data practitioners who want production-grade PyTorch depth at zero cost.

Avoid if

You need structured cohort management or credentialed upskilling across a large data science org.

The Finance Lead

The Finance Lead

Money, total cost of ownership, contracts, procurement math
8.5/10

$0 sticker, $0 year 3 — but ROI measurement is entirely on you.

fast.ai is fully free: courses, fastai library, nbdev, all of it. TCO math is simple; value proof is not.

$0/seat × 50 × 12 = $0. No SSO tax. No overage clause. No auto-renewal trap. A non-profit research institute with no pricing page because there's nothing to price. Rare. The 600-page O'Reilly book is the one optional spend — call it $40-50 one-time per learner who wants it.

Real TCO lives in opportunity cost. 50 developers spending 40+ hours each on 'Practical Deep Learning for Coders' equals 2,000 labor hours. At $75/hour burdened cost, that's $150K in time. deeplearning.ai on Coursera charges $49-$79/month per seat but delivers structured accountability. fast.ai delivers depth and the fastai PyTorch library for production use — deeplearning.ai doesn't ship production tooling.

The tradeoff: ROI is unmeasurable without internal benchmarks. No certificate for online completions. No vendor SLA, no support contract, no procurement process. Procurement teams will love the invoice; finance teams will struggle to justify the headcount hours.

Billing & Procurement8.0

Zero procurement friction on cost; internal approval for 2,000+ labor hours is the actual process hurdle.

Contract Flexibility9.5

No contract, no auto-renewal window, no termination clause — open-source non-profit, exit whenever.

Pricing Transparency10.0

$0 across every tier, publicly visible, no sales call required — pricing page isn't needed when the price is zero.

ROI Clarity5.5

No certificate for online completions and no built-in progress tracking makes skill ROI hard to measure internally.

Total Cost of Ownership9.2

Zero licensing cost; only real TCO is learner labor hours and optional $40-50 O'Reilly book per seat.

Pros

  • $0 all-in, no hidden tiers, no SSO add-on
  • fastai library ships production-ready PyTorch tooling — not just curriculum
  • nbdev solves a real git-conflict problem, adds ongoing developer value
  • No vendor lock-in; open-source, GitHub-available

Cons

  • No completion certificate for online learners — USF in-person only
  • ROI proof requires internal measurement infrastructure
  • No SLA or vendor support contract for production fastai issues
  • Solveit platform details sparse; pricing model post-Answer.AI integration unclear

Right for

Engineering teams that want free, production-grade deep learning education with no procurement overhead.

Avoid if

Your organization needs certifiable outcomes or a vendor with contractual support obligations.

The Domain Practitioner

The Domain Practitioner

Daily hands-on reality in the product's domain — adapts identity per category, same lens
8.2/10

Free PyTorch wrapper that actually gets you training models on day one

fastai's layered API over PyTorch is genuinely well-designed — high-level for fast iteration, drillable to raw primitives when you need them. The ecosystem around it (nbdev, fasttransform, the 30+ hour Part 2 course) is deeper than it looks from the outside.

The fastai library's layered API is the real story here. You can call fit_one_cycle and have a trained ResNet in minutes, then drop into PyTorch-native code when the abstraction leaks. That's a design philosophy, not a happy accident. Keras does something similar but locks you closer to TensorFlow conventions. fastai stays honest about its PyTorch foundation.

nbdev is the sleeper feature. Notebook-to-git conflicts are a daily fight on any team doing exploratory ML work. The docs indicate nbdev2 fully resolves that problem, with Quarto integration for documentation generation. That's friction removed from a workflow that's usually full of it.

The tradeoff worth naming: fastai is a learning platform first, production library second. PyTorch Lightning has more enterprise adoption patterns, better multi-GPU ergonomics at scale. If you're fine-tuning for a research pipeline or learning deep learning seriously, fastai at $0 with 30+ hours of video content is hard to argue against. If you're deploying distributed training across a cluster, Lightning is the default.

Day-3 Reality7.8

High-level API gets you productive fast, but the gap between fastai convenience methods and production-ready PyTorch patterns requires bridging that the docs don't always walk you through.

Documentation Practitioner-Fit8.5

Docs, courses, and the 600-page O'Reilly companion are written by people who clearly use the tools — code-first structure with theory introduced progressively is a practitioner choice, not a marketing one.

Friction Surface7.5

fastchan conda mini-distribution simplifies PyTorch ecosystem installs, which is a real friction point, but the Solveit platform (announced late 2024) adds ecosystem fragmentation to track.

Power-User Depth7.8

The layered API makes advanced PyTorch access possible but discoverable depth past the course curriculum is less obvious — Part 2's 30+ hours of Stable Diffusion content is the clearest signal of ceiling.

Workflow Integration8.0

Jupyter-native via nbdev, runs on Colab and Kaggle Kernels out of the box — fits the actual daily environment of most ML practitioners learning or prototyping.

Pros

  • Layered API lets you stay high-level or go raw PyTorch without fighting the abstraction
  • nbdev solves the Jupyter+git conflict problem that kills collaborative notebook workflows
  • Entire course catalog, library, and community forums at $0 — non-profit structure makes that durable
  • Code-first curriculum means you're training real models on real datasets before touching theory

Cons

  • Production multi-GPU and distributed training patterns are better served by PyTorch Lightning
  • Solveit platform (late 2024, Answer.AI) adds a second environment to the ecosystem with unclear long-term convergence
  • No changelog visible in public materials — hard to track library evolution or breaking changes
  • Beginner-to-advanced path is clear; advanced-to-production path is not

Right for

Software engineers who can code but haven't trained neural networks and want the fastest legitimate path to working deep learning skills.

Avoid if

Your team is deploying distributed training pipelines and needs enterprise-grade MLOps patterns rather than an education-first library.

The Power User

The Power User

Daily human experience, onboarding, polish, learning curve, reliability
8.2/10

Free, coding-first, and genuinely better than most paid alternatives

fast.ai is a free, non-profit deep learning education platform that gets working developers into real models before it touches theory. It's the anti-Coursera.

Everything here is free. Not freemium, not 'free tier with 5 runs a month.' Free. The full Practical Deep Learning for Coders course, the fastai library built on PyTorch, nbdev, the ethics course — all of it. For a working developer who's been burned by deeplearning.ai's $49/month paywall, that lands differently.

The coding-first structure is the real differentiator. You're running models on real datasets in the first lesson. Theory comes after you've already seen it work. nbdev is a quiet gem too — it solves the Jupyter-plus-git problem that anyone who's tried to collaborate on notebooks knows is genuinely painful.

The tradeoff: this isn't a polished SaaS product. There's no changelog, no pricing page because there's nothing to charge. Mobile is web-only and probably rough. The Solveit platform, announced late 2024, is newer territory with unclear feature depth. But for a self-directed developer willing to work? Hard to beat at any price.

Daily Polish6.5

No changelog visible, no pricing page, sparse meta — the website feels maintained by researchers, not a product team.

Learning Curve8.0

The layered fastai API lets you stay high-level or drop into raw PyTorch, which means it scales with you across 30+ hours of Part 2 content.

Mobile Parity4.5

Web-only delivery with Jupyter notebooks — mobile is almost certainly read-only at best, a non-starter for actual coding.

Onboarding Experience8.5

Coding-first structure means learners are running real models immediately, which is the opposite of the usual 'prerequisites' wall.

Reliability Feel7.0

Relies on external environments like Google Colab and Kaggle Kernels, so reliability is partly borrowed from those platforms, not owned.

Pros

  • Entirely free — courses, library, community, all of it
  • Coding-first pedagogy is faster and more motivating than theory-first alternatives like deeplearning.ai
  • nbdev genuinely solves a real Jupyter+git pain point
  • fastai's layered PyTorch API grows with your skill level

Cons

  • Mobile experience almost certainly doesn't support actual coding
  • Product polish is researcher-grade, not SaaS-grade
  • Solveit platform is new and evidence of its feature depth is thin
  • No certificate for online completions — matters to some learners

Right for

Working software developers with basic Python who want to build real deep learning skills without paying or waiting on prerequisites.

Avoid if

You need a structured, credentialed program with mobile access and hand-holding support.

The Skeptic

The Skeptic

Contrarian. Watch-outs, deal-breakers, broken promises, category patterns
8.1/10

Free, honest, 30+ hours deep — and the library actually ships

fast.ai does what it says: free courses, real code first, theory later. No funding theater, no certificate paywall — just a non-profit that's been quietly shipping since 2016.

Three green tells. One: tagline is 'Making neural nets uncool again' — that's self-aware, not hype. Two: the O'Reilly book exists, which means someone with editorial standards reviewed this curriculum. Three: nbdev solves a real, specific problem — git conflicts in Jupyter — not a made-up workflow pain.

The tradeoff is real though. This is education and tooling, not a managed platform. No API, no SLA, no changelog visible. The fastai library is PyTorch-dependent; if PyTorch moves, fastai follows. Compared to deeplearning.ai's Coursera offering, fast.ai gives you zero certificates for the free track — USF in-person students only.

Answer.AI acquisition in late 2024 is the watch item. Non-profits merging into new entities can drift. The Solveit platform is early and thin on public detail. But 'Practical Deep Learning for Coders' with 30+ hours of video and an active forums community is durable. This isn't vaporware.

Competitive Differentiation7.8

Code-first pedagogy is a genuine gap vs. deeplearning.ai's theory-heavy Coursera path, but Hugging Face courses are closing that distance fast.

Exit Portability9.0

It's all open-source on GitHub, PyTorch underneath — if fast.ai disappears tomorrow, the notebooks and library remain forkable.

Long-term Viability7.2

Non-profit structure and Answer.AI merger add uncertainty; no public changelog visible, and Solveit platform details are thin as of late 2024.

Marketing Honesty9.2

Tagline is deliberately anti-hype; pricing page is honest that certificates require in-person USF enrollment — no dark patterns.

Track Record Match8.5

Jeremy Howard and Rachel Thomas have shipped courses, a library, nbdev, and an O'Reilly book — pattern matches durable open-source educator, not abandoned MOOC.

Pros

  • Fully free — no freemium trap, no certificate upsell for the core curriculum
  • nbdev solves a specific real problem (Jupyter + git), not a synthetic one
  • PyTorch foundation means you're learning transferable primitives, not a walled garden
  • 30+ hours of video content in Part 2 alone — substantial, not a teaser

Cons

  • No API, no SLA, no changelog — hard to track whether it's actively maintained
  • Answer.AI merger in late 2024 introduces directional uncertainty
  • Solveit platform is new and evidence-thin — could go either way
  • No certificates on the free track; Coursera's deeplearning.ai wins on credentials

Right for

Working developers who want practical PyTorch skills without a paywall or theory-first gatekeeping.

Avoid if

You need employer-recognized credentials or a managed platform with SLAs and support.

Buyer Questions

Common questions answered by our AI research team

Pricing

Is Practical Deep Learning for Coders free?

Yes, fast.ai courses are free. The product description explicitly identifies them as free courses.

Features

What Python library does fast.ai use for deep learning?

fast.ai uses PyTorch as its deep learning framework, accessed through the fastai Python library built on top of PyTorch.

Features

What problem does nbdev solve for Jupyter notebooks and git?

nbdev solves the git conflict problem with Jupyter notebooks. Previously, using git with Jupyter could create conflicts and break notebooks; nbdev2 fully resolved this issue.

Features

What courses does fast.ai currently offer?

fast.ai currently offers two courses: Practical Deep Learning for Coders and How to Solve it With Code. A book companion (Practical Deep Learning for Coders with fastai and PyTorch) is also available.

Features

Does fast.ai teach theory before coding?

No. fast.ai structures courses around hands-on coding first, with theory introduced progressively rather than as a prerequisite.

Product Information

  • Company

    fast.ai
  • Founded

    2016
  • Pricing

    Free
  • Free Plan

    Available

Platforms

web

About fast.ai

fast.ai is a non-profit research institute based in San Francisco that publishes free online deep learning courses and develops the open-source fastai PyTorch library.

Resources

Documentation

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