Overview

AI Mastering is an automated music-mastering service for musicians and producers who want adjustable loudness and analysis alongside the processing. Its mix of online, API and offline desktop access is useful, though the online wait and the desktop version’s computer-dependent file ceiling shape the choice of workflow.

Automatic processing aims to move music toward commercial sound, with a limiter for balancing loudness and dynamic range. Reference-track matching, WAV export and configurable loudness targets round out a service that offers more control than a one-click finish, without making the result entirely hands-off.

Key features

The web interface accepts files by drag and drop, supports WAV, MP3 and MP4 input, and allows adjustment of target loudness, mastering level and output format. Spectrum and loudness analysis help users inspect a track while making those choices. That combination suits people who want to guide the result; those seeking a fully unattended workflow may have less reason to use the extra controls.

A bass-preservation option can reduce attenuation in low frequencies. The maker says output can reach 24 kHz when the source sample rate is at least 48 kHz and the same rate is selected in custom settings, so that high-frequency capability depends on both the source and the chosen setting.

The API supports audio upload and download, mastering, and changes to target loudness and mastering level. Its documentation links JavaScript (Node) and Ruby client libraries and tutorials, giving developers starting points for integration. The maker says its focus is shifting toward the offline desktop version rather than the API, which makes the offline option the more aligned choice for users planning around the maker’s current direction.

The offline version does not share the online service’s file limitations; its maximum file size depends on the computer’s memory. Online waiting time cannot be shortened, and the maker suggests offline use to reduce it. The service also says users retain full control over mastered tracks, with no service restrictions.

Pricing

The Free Plan is free, billed $0 / Month, and includes Unlimited Mastering. It is a practical fit for users who want ongoing access without a subscription charge or a stated mastering quota. WAV export, loudness targets and reference track matching are supported.

The free plan’s appeal is straightforward, but it does not remove the online waiting time or the online file limitations. Users with larger files or little tolerance for waiting should consider the offline version, whose maximum file size is governed by computer memory.

Platforms

AI Mastering is available on web, through an API and as offline desktop software. Listed platforms also include Android, iOS, Linux, macOS, Windows, extension and self-hosted. The range accommodates both browser-based mastering and local workflows, although online processing remains subject to waiting.

Who it's for

AI Mastering is best suited to musicians and producers who want free automated mastering but still value control over loudness, mastering level and output format. Its analysis tools and reference-track matching are relevant to users who want to assess a track rather than simply submit it for processing. Developers can use the API, while people handling large files or prioritizing shorter waits have a stronger case for the offline version.

It is a weaker fit for anyone who needs online processing to finish on a predictable schedule: the wait cannot be shortened. Users who depend on API development should also weigh the maker’s stated shift in focus toward the offline version.

Pros and cons

Pros: Unlimited mastering for free lowers the barrier for repeated use without a stated mastering quota.
Pros: Target loudness, mastering level, output format and audio analysis give users meaningful ways to guide and examine processing.
Pros: The offline version avoids the online service’s file limitations, with file size instead dependent on computer memory.
Cons: Online waiting time cannot be shortened, making the browser workflow less suitable when turnaround matters.
Cons: The maker’s focus is shifting away from the API and toward offline desktop software, a consideration for users building around the API.

Alternatives

Choose Auralith Forge if you prefer a one-time payment option: its free plan offers three full-length masters and unlimited 30-second previews, while an extra master costs 2.99 EUR per once with no subscription.

Matchering is a free, GPLv3 open-source option for users who want software available on Linux, macOS, Windows, web or self-hosted deployments.

TrackGleam is a fit for users seeking unlimited free mastering with WAV and MP3 output and no watermark or sign-up, across Android, iOS and web.

Consider SoundBoost.ai if its project-based revision model suits you: the free plan provides 10 revisions per project but no finalizing or downloads, while the annual Unlimited plan costs 48.00 USD per year.

SongUp AI is a web-based alternative for users looking for instant song creation, with three free instant songs for personal use and a Pro plan at 9.99 USD per month.

Tunr may suit users who want a free mastering key by email on macOS or Windows; its free plan counts per machine and allows three masters before a licence key.

HanoLab Mastering is an API and web option for users who prefer a monthly credit allowance: its free plan provides 30 credits per month and up to five Studio tracks monthly, with MP3 export marked by a watermark.

MasterForge is another web-based option.

Browse AI mastering tools for more options in the category.

Verdict

AI Mastering is a strong fit for musicians and producers who want unlimited free mastering with adjustable loudness, analysis and reference-track matching. Choose it for that combination of control and no stated mastering quota; look elsewhere, or use its offline version, if online waiting or file constraints are incompatible with your workflow.

	AI Mastering	Optimus
Free plan	Yes	No
Free trial		Yes
Paid from	Free
Platforms	Android, api, extension, iOS, Linux, macOS, self-hosted, Web, Windows	macOS, Windows
Free plan	Yes	No
Reference track matching	Yes
WAV export	Yes
Loudness targets	Yes
Input formats	WAV, MP3, MP4
Supported platforms		plugin

AI Mastering vs Optimus

AI Mastering

Optimus