Harmonics Calc
Get a free API key + new tools as they ship
100 calls/day, no card, no spam. Built by one person, in public.
About Harmonics
Harmonics was built for the moment you just need to handle this task and move on — no signup, no upload to a third-party server. Processing runs locally in your browser using modern Web APIs. Nothing is uploaded, nothing is logged, and there is no quota to worry about for casual use. It is one of about a hundred utility tools that share the same philosophy: do one thing, do it well, get out of your way.
When you'd reach for Harmonics
You're hitting the daily limit of a paid SaaS and need a backup option for a single quick job.
Marketers and ops people whose primary tool is metered.
Stay productive without burning credits.
You're on a public or shared machine and don't want to leave traces of what you're working on.
Travelers, contractors, anyone working from a friend's computer.
Nothing is uploaded, nothing persists if you're not signed in.
You're cleaning up a folder of files that accumulated over a project and need to standardize them.
Designers, writers, and developers wrapping up deliverables.
Drop each file in, copy the output, move on.
You need to handle a one-off task right before a meeting and don't have time to install anything.
Anyone working remotely on a borrowed or restricted machine.
Open the page, get the result, paste it into your doc — under a minute.
Frequently asked about Harmonics
- Can I use Harmonics commercially?
- Yes. The output of Harmonics belongs entirely to you, with no licensing restrictions.
- Do I need to create an account to use Harmonics?
- No. Harmonics works without any signup. We only ask for an email if you decide to subscribe to a paid plan.
- Are my files uploaded to a server when I use Harmonics?
- Harmonics processes everything in your browser using local APIs. Your files never leave your device.
- Does Harmonics work on mobile?
- Yes, Harmonics is fully responsive and tested on iOS Safari and Android Chrome.
- Will Harmonics change my original file?
- Never. Harmonics only reads your input file and produces a new output file.