Best Spaced Repetition Software for Vocabulary (2026): Ranked by Evidence

This guide is for serious learners who want more than a mobile app, and who want to know why a tool schedules a review the way it does, not just that it has good reviews. If you’re looking for a beginner-friendly mobile app to build a daily vocabulary habit instead, our guide to the best vocabulary learning apps is a better starting point, it covers language-specific tools like Memrise and Clozemaster rather than the general-purpose power tools below.

Best Spaced Repetition Software for 2026

Anki

Anki is the benchmark for serious spaced repetition. It’s widely used by medical students, language learners, and academics who need maximum control over how their reviews are scheduled and structured.

Key Features

• FSRS scheduling by default, with SM-2 available for existing collections that haven’t switched
• Flexible card templates with multiple fields
• Large ecosystem of community add-ons
• Detailed learning statistics and progress tracking
• Cross-platform sync via AnkiWeb

Why You’ll Like It

Anki offers unmatched flexibility, and its scheduling has caught up to the current state of the art. You can tailor the system exactly to your needs, whether you’re learning vocabulary, medical terminology, or complex academic material. Its large community means there are countless shared decks and extensions available.

Things to Keep in Mind

Anki has a steep learning curve, and the interface feels dated compared to modern apps. FSRS needs roughly 1,000 reviews before its personalisation kicks in meaningfully, until then it runs on default parameters that behave similarly to SM-2. Because Anki is open-source, there are several similarly named apps on app stores that are not part of the official Anki ecosystem and do not sync with AnkiWeb.

One way to reduce the setup burden is to use AI tools to generate card content rather than building decks manually. The best practices for AI vocabulary learning guide covers a practical Anki workflow that combines AI-generated cards with FSRS scheduling, worth reading if you want to get the most out of Anki without spending hours on deck creation.

The Bottom Line

Anki remains one of the most powerful spaced repetition tools available, and its move to FSRS closed the one real gap it had against newer, more adaptive competitors.

Best For

Advanced learners, students, and power users who want maximum customisation and a current, published scheduling algorithm.

Brainscape

Brainscape is a spaced repetition platform designed to make SRS more approachable without sacrificing effectiveness. Instead of algorithmic scheduling like SM-2 or FSRS, it uses Confidence-Based Repetition, a proprietary system built around how sure you feel about each answer.

Key Features

• Confidence-based spaced repetition system (rate each card 1 to 5)
• Pre-made, expert-certified decks for common subjects and exams
• Simple flashcard creation and review flow
• Web and mobile app synchronisation
• Structured, guided learning experience

Why You’ll Like It

Brainscape removes much of the friction associated with traditional SRS tools. The guided structure makes it easier to stay consistent, especially if you want effective spaced repetition without spending time on setup or configuration.

Things to Keep in Mind

Customisation is more limited than Anki or SuperMemo, and because CBR is proprietary, it hasn’t been independently benchmarked against FSRS or SM-2 the way those algorithms have. You’re trusting Brainscape’s own claims about its effectiveness rather than a published, testable formula.

The Bottom Line

Brainscape is a strong choice for learners who want the benefits of spaced repetition in a more guided, user-friendly format, with more depth than a mobile app but less complexity than Anki.

Best For

Learners who want structured spaced repetition without a steep learning curve.

RemNote

RemNote is a hybrid tool that combines spaced repetition with structured note-taking, making it fundamentally different from traditional flashcard apps.

Key Features

• Integrated note-taking and flashcards
• Automatic conversion of notes into review prompts
• SM-2 scheduling by default, with FSRS available as an alternative scheduler
• Markdown and outlining support
• Cross-device synchronisation

Why You’ll Like It

If your learning process already involves taking detailed notes, RemNote reduces duplication. Notes and flashcards live in the same system, making it easier to reinforce complex ideas over time, and you’re not stuck with SM-2 if you want the more current scheduler.

Things to Keep in Mind

RemNote has a learning curve and may feel heavy if you only want quick vocabulary drills. FSRS is opt-in rather than the default, so unless you switch it on, you’re scheduling reviews with the older algorithm.

The Bottom Line

RemNote is ideal if spaced repetition is part of a broader system for managing and retaining knowledge, not just drilling isolated words.

Best For

Students and advanced learners who combine note-taking with long-term memory building.

SuperMemo

SuperMemo is the origin of the algorithms that most other SRS tools are built on, and its 2026 release, SuperMemo 20, is the most significant update in the category this year. Instead of committing to one scheduling formula, SM20 runs five algorithms at once on your own review data and lets the best performer earn more weight in your schedule automatically.

Key Features

• Algorithm Arena: five spaced repetition algorithms, including FSRS, competing on your personal memory data
• Incremental reading: import and process articles, PDFs, and video directly into your review queue
• Hierarchical knowledge organisation
• Detailed memory and retention analytics, including post-lapse forgetting curves
• Decades of published, peer-reviewed research behind the underlying method

Why You’ll Like It

For users interested in the science behind memory and learning, SuperMemo offers unmatched depth, and SM20 is the first version to stop betting on a single algorithm. Rather than trusting one formula for every learner, it tests several against your actual results and adjusts automatically.

Things to Keep in Mind

The interface is complex and not beginner-friendly. It requires a significant time investment to learn and is less polished than newer tools, and full algorithm optimisation for SM-20 and FSRS may require access to SuperMemo’s own API rather than working entirely offline.

The Bottom Line

SuperMemo is a powerful but demanding tool, and the SM20 Algorithm Arena makes it arguably the most rigorously evidence-driven option on this list, at the cost of a steep learning curve.

Best For

Researchers, academics, and experienced learners who want a highly optimised SRS system and don’t mind paying a one-time fee for it.

Mochi

Mochi is a modern spaced repetition app designed for learners who want simplicity without sacrificing effectiveness. It strips away visual clutter and advanced configuration in favour of a clean interface and a smooth daily review experience.

Key Features

• Clean, distraction-free flashcard interface
• Built-in spaced repetition algorithm (unpublished)
• Markdown support for formatting cards
• Math and code-friendly card creation
• Cross-platform support (desktop and mobile)

Why You’ll Like It

Mochi is ideal if Anki feels overwhelming or outdated. Creating cards is fast, reviews are predictable, and the interface stays out of your way. The Markdown-based editor appeals to learners who value structured, text-first content without complex templates.

Things to Keep in Mind

Mochi offers fewer customisation options than power-user tools like Anki or SuperMemo, and because the scheduling algorithm isn’t published, there’s no way to independently confirm how it compares to FSRS or SM-2. There’s also a smaller ecosystem, no massive add-on library or community deck marketplace.

The Bottom Line

Mochi is a strong choice for learners who want a modern, low-friction daily workflow, with the tradeoff that its scheduling logic is a closed box rather than a published, auditable formula.

Best For

Learners who want a minimalist SRS with a modern interface and low setup overhead.

Obsidian

Obsidian is not a traditional spaced repetition app, it’s a powerful knowledge management tool that can be extended into an SRS system through community plugins.

Key Features

• Markdown-based note system with local file storage
• Bidirectional linking and graph visualisation
• Spaced repetition via community plugins, algorithm depends on which one you choose
• Full control over data and structure
• Offline-first and privacy-focused

Why You’ll Like It

Obsidian shines if you want your learning system to connect ideas, not just memorise isolated facts. Instead of creating standalone flashcards, you can turn notes, definitions, and concepts into review prompts directly within your knowledge base.

Things to Keep in Mind

Spaced repetition is not native to Obsidian, it requires plugins and manual setup, and which algorithm you actually get depends on the plugin. There’s a learning curve, and it’s not optimised for quick, casual flashcard review out of the box.

The Bottom Line

Obsidian is best viewed as a knowledge-first system with optional spaced repetition bolted on, not a flashcard app with a fixed, known algorithm.

Best For

Advanced learners, researchers, and note-takers who want spaced repetition integrated into a personal knowledge system.

Readwise

Readwise applies spaced repetition principles to highlights from books, articles, PDFs, and online content, helping learners retain what they read instead of forgetting it over time.

Key Features

• Spaced review of highlights and notes
• Integration with reading and note-taking tools, including Obsidian and Notion
• Daily review system
• Focus on long-term knowledge retention
• Sync across devices

Why You’ll Like It

If much of your learning comes from reading rather than flashcards, Readwise fills an important gap. Instead of manually turning highlights into cards, it reinforces key ideas automatically through regular review.

Things to Keep in Mind

Readwise is not a traditional flashcard system and is less suited for drilling isolated vocabulary. There’s no permanent free tier, only a 30-day trial, and it works best as a complement to a dedicated SRS tool rather than a replacement.

The Bottom Line

Readwise is a powerful companion tool for learners who want to remember what they read and integrate spaced repetition into a broader learning workflow.

Best For

Readers, knowledge workers, and learners who want long-term retention of highlights and notes.

Comparison Table: The Best Spaced Repetition Software at a Glance

Prefer a quick overview? Below, you’ll find a quick comparison table to help you choose the best option for your learning style and goals.

A note on the evidence column: “Strongest” doesn’t mean the app will definitely work better for you, real-world results depend on consistency and card quality as much as algorithm quality. It means the scheduling logic has been published and independently tested, so you’re not relying on the company’s marketing to know whether it works.

Quick Guide: Which Tool Fits You?

Choose Anki if you want maximum control, deep customisation, and a scheduler (FSRS) that’s caught up to the current state of the art.

Choose Brainscape if you want a guided, easy-to-use system with minimal setup and more depth than a mobile app.

Choose RemNote if you want to turn notes into flashcards automatically and build long-term knowledge in one system, and don’t forget to switch on FSRS if you want it, it isn’t the default here.

Choose SuperMemo if you want the algorithm itself optimised automatically, SM20’s Algorithm Arena tests five formulas against your own data rather than betting on one.

Choose Mochi if you want a modern, minimalist alternative to Anki that focuses on distraction-free daily reviews, and you’re comfortable not knowing exactly how the scheduling works under the hood.

Choose Obsidian if you want spaced repetition embedded in a broader personal knowledge system rather than a standalone flashcard app.

Choose Readwise if your main goal is retaining insights from books, articles, and highlights rather than drilling vocabulary.

If you’re not ready for any of these and just want a beginner-friendly mobile app, start with our guide to the best vocabulary learning apps instead.

What the 2026 research on spaced repetition actually shows

The core finding, that spaced practice produces far better long-term retention than massed study, has been replicated so many times it’s no longer controversial. The 2008 Cepeda meta-analysis, covering 317 studies, remains the landmark reference, and its conclusions have held up consistently in every major review since.

What’s newer, and more directly relevant to software choice, is research on algorithm quality specifically. A 2021 large-scale randomised controlled trial published in npj Science of Learning found that learners, holding study time constant, whose sessions were scheduled by a machine learning algorithm retained content over 69% longer than those using standard heuristics.

The FSRS-versus-SM-2 comparison sits inside that same research line. FSRS is trained on real review data rather than a fixed formula, and independent benchmarks on hundreds of millions of Anki reviews report it needs roughly 20 to 30% fewer reviews than SM-2 to hold the same retention target.

This matters for the tools on this list. Anki, RemNote, and SuperMemo 20 all publish or expose their algorithms, independent researchers can study them. Brainscape, Mochi, and Readwise use proprietary or unpublished variants. That’s not necessarily a dealbreaker, any genuine SRS outperforms random flashcard shuffling, but it’s the honest answer to why Anki and SuperMemo sit at the top of this list.

For a full breakdown of the underlying research, see our guide on how spaced repetition builds vocabulary fast and the spaced repetition vs traditional learning comparison, the latter covers the Cepeda meta-analysis and Dunlosky et al. in more depth.

What Makes Great Spaced Repetition Software?

Not all spaced repetition tools are created equal. The best ones balance algorithm quality, usability, and flexibility so you can review efficiently without friction.

When comparing SRS tools, focus on these core factors:

• Algorithm transparency: the best tools publish how their scheduling works, so independent researchers can test whether it actually optimises retention. Proprietary algorithms may work well, but you’re taking the company’s word for it. This matters even more once you’re the one writing the cards. If you’re the person typing “la colazione = breakfast” into a deck yourself, the algorithm decides when you see the card again, but you still decide how clear the card is. A well-written card on a transparent, older algorithm beats a sloppy card on the newest scheduler.
• Cross-platform access: reliable sync across desktop and mobile is essential for consistent daily reviews.
• Efficient content creation: bulk imports, templates, and media support save time as your deck grows.
• Progress tracking: clear statistics help identify weak areas and improve long-term retention.

A strong spaced repetition system minimizes wasted reviews and keeps your focus on the items you’re most likely to forget. If you are still weighing whether SRS is the right method for your learning style, how spaced repetition compares to traditional language learning is worth reading before committing to a tool.

Cost Analysis: Free vs. Premium Spaced Repetition Software

Most spaced repetition tools offer both free and paid options, and for many learners, free versions are enough to get started.

Free plans typically include:

• Anki’s full desktop app, including FSRS scheduling, at no cost
• SuperMemo 15, the previous major version, remains free indefinitely
• Basic flashcard creation, daily reviews, and progress tracking on Brainscape, RemNote, Mochi, and Obsidian’s free tiers

Premium plans, with actual figures:

• Brainscape Pro: $19.99/month, or as low as $8/month billed annually
• RemNote Pro: $8 to $10/month depending on billing cycle, or a one-time $395 for lifetime access
• SuperMemo 20: a one-time $68 purchase, no subscription
• Mochi Pro: $5/month for cross-device sync verify
• Obsidian Sync (optional): $4 to $5/month
• Readwise: $9.99 to $12.99/month, no permanent free tier

Bottom line: start with a free version to build consistency. Anki’s free desktop app, running current FSRS scheduling, is enough for most learners to never need to pay for anything at all. Upgrade only if you hit clear limitations in usability, syncing, or review control.

Start Building Vocabulary That Actually Sticks

Choosing the right spaced repetition software can make a measurable difference in how efficiently you build and retain vocabulary. The best choice depends on how much control, guidance, and flexibility you want in your learning system, and now, on whether the algorithm behind it is one anyone outside the company can actually verify.

If you want maximum customisation and a scheduler that’s caught up to 2026, Anki remains the benchmark. If you want the algorithm question taken out of your hands entirely, SuperMemo 20 is the only tool here that runs FSRS and its own models side by side and picks the winner for you. For learners who prefer a more guided, beginner-friendly experience with less setup, Brainscape offers a smoother entry point.

There’s no single “best” option for everyone, the most effective spaced repetition tool is still the one you’ll use consistently, even if it’s running last decade’s algorithm.

A Simple Action Plan

• Upgrade only when you hit clear limitations around syncing, workflow, or review control
• Start with a free version to build the habit (Anki desktop, with FSRS already on by default, or Brainscape’s free tier)
• Commit to short daily reviews for at least two weeks
• If you’re already on Anki with an older collection, check your deck options and confirm FSRS is switched on rather than assuming it is

A few more useful guides:
▪ How Spaced Repetition Builds Vocabulary Fast
▪ Spaced Repetition vs Traditional Learning: Which Works?
▪ Best Vocabulary Learning Apps (SRS & Memory-Focused)

Frequently Asked Questions