maratoolFree online tools
No accounts. No installs. Nothing leaves your browser.
Browse by vertical9 categories · 536 tools
Medical calculators, scores, scales, references
CSV, JSON, YAML, XML, units, base
Inspect, decode, generate, hash, parse
Convert, compress, remove background, optimize
Margin, break-even, tax, ROI, Amazon & Etsy fees
Diff, format, extract, transform, count
Mortgage, loans, compound interest, CAGR
Merge, split, extract text, metadata
Pick, convert, contrast, palette, harmony
Generate fake chats, posts, screenshots
QR codes, UTM links, barcodes
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Why maratool?
No sign-ups. No "free tier" limits. maratool runs 536+ tools directly in your browser. Your files stay on your device. Results appear instantly. The one tool that needs a server is the Instagram video downloader, because Instagram blocks direct browser fetches; the privacy page explains exactly what it does.
Frequently asked questions
Are these tools really free?
Yes, every tool on maratool is completely free with no sign-up, no limits, and no hidden paywalls. The site is supported by ads.
Is my data safe?
Yes. Almost every tool runs entirely in your browser using JavaScript. Your files and text stay on your device and nothing is uploaded. The one exception is the Instagram video downloader, which has to proxy through a small server because Instagram blocks direct browser fetches. The privacy policy documents it in detail.
Do I need to create an account?
No. There are no accounts, no sign-ups, and no login walls. Just open a tool and start using it immediately.
What tools are available on maratool?
maratool offers 536+ tools across 9 categories: converters, PDF, text, image, color, developer, marketing, mockups, and medical calculators (Health). Almost every tool runs in your browser.