Mass Fraction
Get a free API key + new tools as they ship
100 calls/day, no card, no spam. Built by one person, in public.
About Mass Fraction
Mass Fraction is a free, browser-based utility designed to make this task as quick and frictionless as possible. Everything happens client-side, which means your files and data never leave your machine. The interface is intentionally minimal so you can focus on the task instead of learning the tool. Like everything else in the utility collection, it is free, ad-light, and works on mobile as well as desktop.
When you'd reach for Mass Fraction
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.
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.
Frequently asked about Mass Fraction
- Will Mass Fraction change my original file?
- Never. Mass Fraction only reads your input file and produces a new output file.
- Does Mass Fraction work on mobile?
- Yes, Mass Fraction is fully responsive and tested on iOS Safari and Android Chrome.
- Can I use Mass Fraction commercially?
- Yes. The output of Mass Fraction belongs entirely to you, with no licensing restrictions.
- Do I need to create an account to use Mass Fraction?
- No. Mass Fraction works without any signup. We only ask for an email if you decide to subscribe to a paid plan.
- What browsers does Mass Fraction support?
- Every modern browser released in the last three years: Chrome, Firefox, Safari, Edge, Brave, Opera.
