
Create iOS and Android apps with React and Ionic

Smallpdf
iLovePDF
Convertio
CloudConvert
PDF24
Stirling PDF
Adobe Acrobat DC
500+ free file tools (PDF, image, audio, video, data, 3D) that run entirely inside your browser via WebAssembly. No uploads, no account, works offline, available in 25+ languages.

Website, pricing, platforms and company facts side by side.
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| Website | reactionic.github.io | gottrix.app |
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| Platforms | — | |
| Company | — | Startup from Germany · 2026 |
| Listed in |
In their own words, as submitted to SaaSHub.


No description of React-Ionic yet.
Almost every "free" online file converter works the same way: you upload your file to a server, it gets processed there, and you download the result. gottrix works differently. Every single conversion, from compressing a PDF to trimming an MP3 to converting a HEIC photo, runs entirely...
What each product offers, as listed by its team.


Possible disadvantages
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How often each product is chosen within a category, 0–100% relative to the other.


As answered by people managing React-Ionic and Gottrix.app.
Gottrix.app's answer:
Astro and TypeScript for the site itself, Tailwind CSS for styling, and WebAssembly for the actual conversion engines (ffmpeg.wasm for audio/video, pdf.js and pdf-lib for PDF, libheif and Squoosh for images), all running inside sandboxed Web Workers with zero network access.
Gottrix.app's answer:
Anyone handling files they'd rather not hand to a third-party server: freelancers and professionals working with contracts, invoices or client documents, students and privacy-conscious individuals doing everyday conversions, and international users thanks to 25+ language support. Also a good fit for regulated or confidential business contexts where uploading a file anywhere isn't an option.
Gottrix.app's answer:
gottrix started from a simple frustration: nearly every "free" online file converter requires uploading your document to someone else's server, even for something as routine as compressing a PDF or converting a photo. gottrix was built to remove that requirement entirely. Everything runs in the browser via WebAssembly, so the file never leaves the device in the first place.
Gottrix.app's answer:
Every conversion runs 100% client-side in WebAssembly - files never touch a server, provably so (you can verify it yourself in DevTools' Network panel, or just try it in airplane mode after the first visit). Most converters ask you to trust a privacy policy; gottrix lets you check. On top of that: 500+ tools across PDF, image, audio, video, data and 3D formats in one place, no account, no signup, available in 25+ languages.
Gottrix.app's answer:
Competitors like Smallpdf, iLovePDF, Convertio and CloudConvert upload your file to their servers to process it - fine for a random image, risky for a contract, medical record, or anything confidential. gottrix never uploads anything, so there's nothing to leak, no server log of what you converted, and no need to trust a third party with sensitive documents. It's also free without the usual catches: no per-file limits, no watermarks, no forced account, and it keeps working offline once loaded.
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