Simple Interest Monthly
Get a free API key + new tools as they ship
100 calls/day, no card, no spam. Built by one person, in public.
About Monthly Simple Int
Monthly Simple Int solves a specific problem that comes up daily for anyone dealing with this task: doing it once, fast, without an account. 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. If you find yourself doing this regularly, the rest of the utility suite covers most adjacent tasks with the same approach.
When you'd reach for Monthly Simple Int
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 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 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 Monthly Simple Int
- What browsers does Monthly Simple Int support?
- Every modern browser released in the last three years: Chrome, Firefox, Safari, Edge, Brave, Opera.
- Do I need to create an account to use Monthly Simple Int?
- No. Monthly Simple Int works without any signup. We only ask for an email if you decide to subscribe to a paid plan.
- Is Monthly Simple Int really free?
- Yes — Monthly Simple Int is free for unlimited personal use, with no account required and no watermark on the output.
- Will Monthly Simple Int change my original file?
- Never. Monthly Simple Int only reads your input file and produces a new output file.
- Does Monthly Simple Int work on mobile?
- Yes, Monthly Simple Int is fully responsive and tested on iOS Safari and Android Chrome.