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Lacuna

lacuna.fm

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Spec score 9.0 #1 of 36 in Audio Converter Software

What it is

Lacuna turns a short idea into song lyrics and can send them to its music generator to create a track with AI vocals. The editor supports line-by-line rewrites, syllable counts, automatic rhyme highlighting, and rhyme suggestions ranked by meaning. It supports nine languages, with phonetic rhyme support for English, Spanish, Chinese, Japanese, and Korean. Automatic snapshots let users restore an earlier take after AI edits. Lacuna describes the workspace for songwriters, rappers, topliners, producers, and first-time writers, and says generated or edited lyrics may be recorded, released, and used commercially. The free plan provides 120 credits per month without requiring a credit card; each lyrics AI use costs five credits, and unused credits do not roll over. Pricing lists paid service from $9.50/mo (annual), while Basic is $19 a month. Audio downloads require a subscription, and credit packs alone do not include them. The developer API requires Pro or Ultra and uses credit-based billing. Lacuna lists web, iOS, extension, and API platforms.

Spec sheet

What it does
Lacuna is a browser-based AI music workspace that turns prompts or user lyrics into vocal or instrumental songs and supports later editing, enhancement and sharing.Read 15 Oct 2026 · lacuna.fm
Intended users
The maker describes the lyrics workspace for songwriters, rappers and topliners, producers, and first-time writers.Read 29 Sep 2026 · lacuna.fm
Free plan
YesRead 21 Sep 2026 · lacuna.fm
Paid from
9.5Read 21 Sep 2026 · lacuna.fm
Integrations
The developer API can be called through REST, a typed TypeScript client, a command-line toolkit or MCP.Read 15 Oct 2026 · lacuna.fm
Support
Support is offered through email and a Discord creator community.Read 15 Oct 2026 · lacuna.fm
Headquarters
London, United KingdomRead 28 Sep 2026 · lacuna.fm
Company
Lacuna says it is operated by JOYLINK LTD and lists its location as London, United Kingdom.Read 29 Sep 2026 · lacuna.fm
Account deletion
The privacy policy says deleting an account ends access and disables public sharing but does not automatically erase all stored account information or content.Read 29 Sep 2026 · lacuna.fm
AI lyrics
Its Lyrics Agent chats with users to draft and revise lyrics in an adjacent editor, including line or section editing.Read 15 Oct 2026 · lacuna.fm
AI mastering
The same workspace offers mastering with genre presets or an uploaded reference track.Read 15 Oct 2026 · lacuna.fm
API access
Music API access is limited to Pro and Ultra subscriptions and uses credits.Read 15 Oct 2026 · lacuna.fm
API behavior
Music generation is asynchronous, with polling or SDK waitFor support and signed completion or failure webhooks.Read 15 Oct 2026 · lacuna.fm
API limits
The API creation endpoint permits 60 requests per minute per key, with default concurrency of 10 Pro tasks or 20 Ultra tasks.Read 15 Oct 2026 · lacuna.fm
API lyrics limitation
Vocal API requests do not write lyrics automatically; the calling application must supply them.Read 15 Oct 2026 · lacuna.fm
API restriction
The maker says API access requires Pro or Ultra and uses credit-based billing.Read 29 Sep 2026 · lacuna.fm
App availability
The maker announced its iPhone app on September 4, 2026, using the same account as the web service.Read 15 Oct 2026 · lacuna.fm
Commercial rights
The commercial license grants worldwide perpetual ownership and usage rights for qualifying songs created during the license period.Read 15 Oct 2026 · lacuna.fm
Commercial use
The lyrics page says generated and edited lyrics are the user’s to record, release, and use commercially.Read 29 Sep 2026 · lacuna.fm
Company headquarters
The maker identifies London, United Kingdom as its location, while Crunchbase also lists London as headquarters.Read 15 Oct 2026 · lacuna.fm
Company legal name
The operating company is JOYLINK LTD, registered in England and Wales under company number 16157644.Read 15 Oct 2026 · lacuna.fm
Company size and funding
The About page calls Lacuna a remote-first lean startup, and the public Crunchbase page does not show a founded year, employee count or funding total.Read 15 Oct 2026 · lacuna.fm
Company status
Crunchbase lists Lacuna as a private, active, for-profit company.Read 15 Oct 2026 · crunchbase.com
Credit limits
Lyrics AI assistant use costs five credits per use, and pricing says unused credits do not roll over between cycles.Read 29 Sep 2026 · lacuna.fm
Documentation depth
The API documentation publishes endpoint examples, typed methods, webhook handling, authentication, limits and failure-refund behavior, while the MCP page links to SDK, CLI and API reference resources.Read 15 Oct 2026 · lacuna.fm
Downloads
Pricing says audio downloads require a subscription; credit packs alone do not include them.Read 29 Sep 2026 · lacuna.fm
Editor
The lyrics editor supports line-by-line rewrites, syllable counts, automatic rhyme highlighting, and rhyme suggestions ranked by meaning.Read 29 Sep 2026 · lacuna.fm
Independent feature assessment
AI Journey describes Lacuna as combining song generation, lyric editing, section replacement, remixing, stem separation, analysis, mastering, MIDI and video tools.Read 15 Oct 2026 · aijourney.so
Independent pricing listing
SEOFAI lists monthly paid options beginning at $19 and identifies the product as web-based.Read 15 Oct 2026 · seofai.com
Languages
The lyrics workspace supports nine languages, with phonetic rhyme support for English, Spanish, Chinese, Japanese, and Korean.Read 29 Sep 2026 · lacuna.fm
License status
The service is proprietary; its terms say Lacuna owns or licenses the service intellectual property, while the About page identifies Meta Llama 3.2 as a separately licensed component.Read 15 Oct 2026 · lacuna.fm
Limit: advanced control
AI Journey cautions that professional musicians may want more detailed production controls than a browser-based workflow provides.Read 15 Oct 2026 · aijourney.so
Limit: AI output risk
The terms warn that generated audio may contain inaccuracies, artifacts or unintended elements and require users to review outputs before use.Read 15 Oct 2026 · lacuna.fm
Limit: availability guarantee
The terms disclaim guarantees of availability and liability for downtime or service interruptions.Read 15 Oct 2026 · lacuna.fm
Limit: genre interpretation
SEOFAI reports occasional inaccuracies in genre interpretation and says experienced musicians may find customization depth limited.Read 15 Oct 2026 · seofai.com
Limit: independent trust signals
ScamAdviser reports hidden WHOIS ownership, low visitor volume and a recently registered domain, although it still labels the site probably legitimate.Read 15 Oct 2026 · scamadviser.com
Limit: output variability
AI Journey notes that generated quality can vary with the prompt, genre and complexity of the requested track.Read 15 Oct 2026 · aijourney.so
MCP integration
The official lacuna-mcp package works with Claude Code, Claude Desktop, Cursor, Zed and other MCP clients through npm.Read 15 Oct 2026 · lacuna.fm
MIDI tools
Lacuna provides prompt-to-MIDI generation with preview, piano-roll editing and export.Read 15 Oct 2026 · lacuna.fm
Music analysis
Generated tracks expose synchronized lyrics plus key, BPM, chord progression and loudness analysis.Read 15 Oct 2026 · lacuna.fm
Notable news: October 15, 2026
The changelog says Music Agent added workflows for building an instrumental around an uploaded vocal or adding new vocals to an instrumental, with one-click suggested edits.Read 15 Oct 2026 · lacuna.fm
Praise: convenience
AI Journey praises the single ecosystem for combining generation, editing, lyrics, stems, MIDI and mastering without switching applications.Read 15 Oct 2026 · aijourney.so
Rating on Apple App Store
No rating overview because the app has not received enough ratings or reviewsRead 15 Oct 2026 · apps.apple.com
Rating on G2
0.0 out of 5 from 0 reviewsRead 15 Oct 2026 · g2.com
Region editing
Region Edit regenerates only a selected waveform section while keeping the rest of the song intact and lyrics time-aligned.Read 15 Oct 2026 · lacuna.fm
Security and data
The privacy policy says uploaded materials, prompts, generated content, and task records may be retained while available in the service, and says it cannot guarantee absolute security.Read 29 Sep 2026 · lacuna.fm
Security and privacy
The terms state that services are hosted in the United States and that use from elsewhere transfers data there; the iOS listing says user content, identifiers, purchases and coarse location may be linked to the user.Read 15 Oct 2026 · lacuna.fm
Song generation
The Music Agent proposes two musical directions and can generate complete tracks from a description or supplied lyrics.Read 15 Oct 2026 · lacuna.fm
Stem separation
Tracks can be separated into two, four or six stems such as vocals, drums, bass and instruments.Read 15 Oct 2026 · lacuna.fm
System requirements
The iOS app requires iOS 17 or later; its Mac compatibility requires macOS 14 or later with an Apple M1 chip or newer.Read 15 Oct 2026 · apps.apple.com
Version history
The editor saves snapshots automatically as the AI edits and lets users restore an earlier take.Read 29 Sep 2026 · lacuna.fm

Plans and prices

Basic $9.50 a month $114 prepaid yearly 2,500 monthly credits · ≈100 songs · commercial use · unlimited audio downloads · 5 concurrent generations Read 15 Oct 2026 · lacuna.fm
Pro $24.50 a month $294 prepaid yearly 7,500 monthly credits · ≈300 songs · commercial use · downloadable license PDF · unlimited audio downloads · 10 concurrent generations Read 15 Oct 2026 · lacuna.fm
Ultra $49.50 a month $594 prepaid yearly 25,000 monthly credits · ≈1,000 songs · commercial use · downloadable license PDF · unlimited audio downloads · unlimited sheet music to MIDI · 20 concurrent generations Read 15 Oct 2026 · lacuna.fm
Credit Pack S $50 a month one-time purchase 3,500 credits · Approximately 70 generations Read 21 Sep 2026 · lacuna.fm
Credit Pack M $100 a month one-time purchase 8,000 credits · Approximately 160 generations Read 21 Sep 2026 · lacuna.fm
Credit Pack L $500 a month one-time purchase 50,000 credits · Approximately 1,000 generations Read 21 Sep 2026 · lacuna.fm
Free Free 120 credits per month; no credit card required Free starting credits · audio downloads require subscription Read 15 Oct 2026 · lacuna.fm
Credit Pack S $50, paid once One-time purchase 3,500 credits · ≈70 generations · credits never expire · audio downloads require subscription Read 15 Oct 2026 · lacuna.fm
Credit Pack M $100, paid once One-time purchase 8,000 credits · ≈160 generations · credits never expire · audio downloads require subscription Read 15 Oct 2026 · lacuna.fm
Basic $114 a year $114/year 2,500 monthly credits · ≈100 songs · commercial use · unlimited audio downloads · up to 5 concurrent generations Read 29 Sep 2026 · lacuna.fm
Pro $294 a year $294/year 7,500 monthly credits · ≈300 songs · commercial use · downloadable license PDF · unlimited audio downloads · up to 10 concurrent generations Read 29 Sep 2026 · lacuna.fm
Credit Pack L $500, paid once One-time purchase 50,000 credits · ≈1,000 generations · credits never expire · audio downloads require subscription Read 15 Oct 2026 · lacuna.fm

Every Lacuna plan and price →

Strong points and limits

Strong points

  • Editor supports line rewrites and syllable counts.
  • Rhyme suggestions are ranked by meaning.
  • Supports nine languages.
  • Generated and edited lyrics may be used commercially.

Limits

  • Lyrics AI use costs five credits per use.
  • Unused credits do not roll over.
  • Audio downloads require a subscription.
  • API access requires Pro or Ultra.

Who it suits

Lacuna suits songwriters, rappers, topliners, producers, and beginners looking for help drafting and revising lyrics. It may also suit developers who need an API, provided they have Pro or Ultra access.

Lacuna in depth

Read the full write-up

Lacuna is a lyric-writing workspace that can carry a draft into an AI-vocal track. It suits songwriters who want structured help revising lines as well as a path from words to audio. Its writing tools are substantial, but recurring credits and subscription-only audio downloads make the plan choice consequential.

Overview

A one-line idea can become a lyric, then move to Lacuna’s music generator for a track with AI vocals. That makes Lacuna broader than a lyric prompt tool, though writers focused only on words may not need the audio workflow. The maker says generated and edited lyrics may be recorded, released, and used commercially.

Lacuna is operated by JOYLINK LTD, based in London, United Kingdom. Its API offers REST access, a TypeScript SDK, CLI tools, and an MCP server for compatible agents such as Cursor, Claude Code, and Codex. API access requires Pro or Ultra and uses credit-based billing, so it is not an add-on for free or Basic users.

Key features

Drafting and revision

Line-by-line rewrites let writers refine a weak phrase without discarding the rest of a draft. Syllable counts, automatic rhyme highlighting, and meaning-ranked rhyme suggestions support more deliberate revision than a prompt-and-regenerate loop. Song structure controls add another way to shape a draft, while automatic snapshots let users restore earlier takes after AI edits.

Language and audio

The workspace supports nine languages, with phonetic rhyme support for English, Spanish, Chinese, Japanese, and Korean. That distinction matters: multilingual lyric drafting extends beyond the five languages with phonetic rhyme support. Users can send lyrics to Lacuna’s music generator, but audio downloads require a subscription; buying credits alone does not unlock downloads.

Credits, data, and support

Each use of the lyrics AI assistant costs five credits, and unused credits do not roll over between cycles. The privacy policy says uploaded materials, prompts, generated content, and task records may be retained while available in the service, and does not guarantee absolute security. Deleting an account ends access and disables public sharing, but does not automatically erase all stored account information or content. Support is offered by email, feedback form, and Discord.

Pricing

Lacuna is freemium. Its pricing note says paid plans start at $9.50/mo (annual), while the detailed monthly plans are priced separately:

Free: free, with 120 credits/month and no credit card required. It is suitable for trying the workflow, but the credit allowance is small for frequent AI-assisted revision, and audio downloads require a subscription.

Basic: $19 a month, billed monthly, for 2,500 credits/month, approximately 100 songs, and up to 5 concurrent generations. This is the entry paid tier for regular individual use, though it does not include the larger quotas or concurrency of higher plans.

Pro: $49 a month, billed monthly, for 7,500 credits/month, approximately 300 songs, and up to 10 concurrent generations. It is the tier to consider when API access is needed or generation volume outgrows Basic.

Ultra: $99 a month, billed monthly, for 25,000 credits/month, approximately 1,000 songs, and up to 20 concurrent generations. Its higher quota and concurrency suit heavier workloads, but may be excessive for a writer working on occasional songs.

Credit packs are one-time purchases and do not include audio downloads: Credit Pack S is $50 a month for 3,500 credits (approximately 70 generations); Credit Pack M is $100 a month for 8,000 credits (approximately 160 generations); Credit Pack L is $500 a month for 50,000 credits (approximately 1,000 generations). Despite the monthly price wording, these are described as one-time purchases. Packs may help with credit demand, but do not replace a subscription when downloads are needed.

Platforms

Lacuna is available on web, iOS, as an extension, and through an API. That range supports both a browser-based writing workflow and developer integrations, while the API’s Pro-or-Ultra requirement limits access for lower-tier users.

Who it's for

Lacuna fits songwriters, rappers, topliners, producers, and first-time writers who want line-level lyric support and may also want to turn a draft into an AI-vocal track. It is a weaker fit for someone who only needs occasional lyric suggestions, wants downloadable audio without a subscription, or is uncomfortable with the stated data-retention and deletion terms.

Pros and cons

Pro: Line-level rewrites, syllable counts, and meaning-ranked rhyme suggestions offer practical revision tools beyond initial lyric generation.

Pro: Automatic snapshots make it possible to return to earlier drafts after AI edits.

Pro: Lyrics can move into Lacuna’s music generator, and the maker permits commercial use of generated and edited lyrics.

Con: The free plan provides 120 credits/month, while each lyrics-assistant use costs five credits; frequent iteration can consume the allowance quickly.

Con: Audio downloads require a subscription, so credit packs alone are insufficient for a downloadable track.

Con: Credit balances do not roll over, and account deletion does not automatically erase all stored information or content.

Alternatives

AI lyric generators is the broader category for comparing lyric-focused tools; AI music generators is more relevant when audio creation is the priority. For a different mix of platforms and free limits, consider these alternatives:

Prompt Maschine has a free plan with three generation operations per day and two variants per generation, plus Android, iOS, and macOS support; choose it when that platform mix and bounded daily generation suit your workflow.

Lyric Genie offers unlimited songs, basic rhymes and synonyms, 60 minutes of voice recordings, and real-time collaboration on its free plan, with iOS and macOS support; it is worth considering if those free tools and collaboration are more useful than Lacuna’s route to AI vocals.

RhymesLab is web-based and its free plan includes five songs/month, 25 sections/month, 15 Ghost chats/day, and a 14-day Flow trial; choose it when those defined writing limits fit your needs.

FlowTight is an iOS option whose free plan includes voice recording, an AI lyric generator, and three AI beat generations per month; it may suit an iPhone user who wants those beat-generation limits.

LyricDraft is web-based, with a one-time free allowance of 18 signup credits and free manual edits; it is a plausible pick for someone who wants to try a limited credit-based workflow without a card.

RhymeFlux supports Android, iOS, and web; its free tier allows one active song, 15 AI credits every 30 days, and rhyme highlighting on the first 12 bars of the first section, making it a narrower option for occasional use across those platforms.

RHYMEBOOK is available on Android, iOS, and web, with a free tier covering notes, AI suggestions, Ghostwriter chats, demos, and transcription minutes; consider it if that range of tools matters more than Lacuna’s audio-generation path.

Hit Station has a web free plan limited to five new songs and 50 AI generations per month for personal use; its free tier may suit personal experimentation within those caps.

Audio Converter Software is another category to browse if your main task is working with audio files rather than creating lyrics.

Verdict

Choose Lacuna if you want a capable lyric-revision workspace, multilingual support, and a direct route from lyrics to AI-vocal tracks. The strongest reason to look elsewhere is the combination of credit-based use and subscription-gated downloads: writers who need only occasional lyric help, or who want downloadable audio without a recurring plan, will find its limits less appealing.

Verdict

Lacuna offers lyric drafting and revision tools with multilingual support and a route from lyrics to AI-vocal tracks. Check credit use and download requirements before choosing a plan; the annual pricing note lists a starting price of $9.50/mo.

Where Specifiction places it

Alternatives to LacunaAll alternatives →