Overview

Flat brings notation, playback, and real-time collaboration into one workspace, with support for tablature and parts extraction as well as conventional scores. Its range of platforms and import and export formats makes it a flexible option for people moving between devices. The free plan is a practical way to start, but its score cap and the paid cloud-sync requirement are meaningful constraints for regular use.

Key features

Multiple users can write, edit, and comment on the same score in real time from different devices. That makes Flat well suited to shared arranging and classroom work; solo writers who do not need collaboration have less reason to choose it on that strength alone.

MusicXML and MIDI import and export support score interchange, while desktop users can also export PDF, MP3, and WAV. PDF import is less convenient: it requires Power or paid credits. Flat supports more than 180 instruments, including HQ studio instruments on Power. The free plan has 30 instruments; Power adds custom instruments, customizable layouts and notation, and advanced playback.

Users can compose, edit, and play scores offline, but cloud sync requires Power. That distinction works for occasional offline sessions, but people who expect their work to sync across devices will need a paid plan. Power also includes priority support.

Pricing

Plan	Price	What it includes
Flat Basic	Free	Core notation tools, playback, real-time collaboration, MIDI device transcription, 30 instruments, and up to 15 scores. MusicXML and MIDI import; export and print include Flat branding.
Flat Power Monthly	$9.99 per month	Unlimited scores, 180+ instruments including HQ instruments, MusicXML and MIDI import/export, custom instruments, customizable layouts and notation, advanced playback, cloud sync, and priority support.
Flat Power Yearly	$49.99 per year	Power features on an annual subscription, with a stated 58% saving compared with monthly billing.
Flat Power Lifetime	Custom pricing	Lifetime option with premium Power features.
Flat Desktop Free	Free	Free desktop app with up to 15 scores.

The free desktop app is free to download and use, but it does not remove the 15-score limit. Basic also keeps exports and printing branded, while Power removes the score ceiling and expands the instrument and notation toolkit. For regular use, the annual price is substantially lower than paying $9.99 each month, provided an annual commitment suits you. Flat for Education can be tried free for one month; its integrations include Google for Education, Microsoft Office 365, and Canvas.

Platforms

Flat runs on the web, iOS, Android, macOS, and Windows. The desktop app is free to download and use, and offline composing, editing, and playback provide a useful option when internet access is unavailable. Cloud sync, however, is reserved for Power.

Who it's for

Flat is a strong fit for educators, student groups, and musicians who need to collaborate on notation across devices, or who use tablature and parts extraction alongside score writing. Basic can suit smaller projects that stay within 15 scores. Composers with larger libraries, a need for cloud sync, or a preference for advanced playback and more instruments will get more from Power. Those who mainly need a solo notation editor and do not value collaboration may prefer a free alternative.

Pros and cons

Pros

Real-time writing, editing, and commenting support shared scores across devices, useful for ensembles and classroom work.
MusicXML and MIDI import and export, plus desktop PDF, MP3, and WAV export, cover several common score workflows.
Offline composing, editing, and playback let users keep working without a connection.
Web, mobile, Mac, and Windows support gives collaborators several ways to access the app.

Cons

The free plan stops at 15 scores, which can be restrictive for people maintaining a growing catalogue.
Cloud sync requires Power, so offline capability alone does not provide synced work across devices.
PDF import requires Power or paid credits, a drawback for workflows that begin with PDF scores.
Free exports and printing carry Flat branding.

Alternatives

For a broader range of options, browse Music notation software or Music Collaboration Software.

Noteflight is worth considering if you want a web-only tool and can pay $7.95 per month for Premium, which includes unlimited scores, premium notation and formatting, and 85 instruments.
Fender Notion may suit users who prioritize cross-platform notation and tablature with full editing capabilities on its free plan, which also allows unlimited staves.
Dorico is another notation option.
MuseScore Studio is free and open-source, with no limitations or account or subscription requirement; choose it if those terms matter more than Flat's collaboration and cross-device workflow.
LilyPond is free software for Linux, Windows, and macOS.
Sibelius offers a free notation option for users new to music notation, alongside paid plans.
ScoreCloud may fit people who want to notate from singing; its free plan allows 10 songs online with watermarked print.
TuxGuitar is a free guitar tablature editor for Android, Linux, macOS, and Windows.

Verdict

Choose Flat if you need notation and real-time collaboration in a cross-platform app, especially for shared arranging or education. Its free plan makes small projects accessible, while Power adds unlimited scores, cloud sync, more instruments, and advanced tools. Look elsewhere if a 15-score cap, branded free exports, or paid PDF import would disrupt your workflow.

Flat vs Vampr

Flat

Vampr