Last updated 7 October 2026
Many free file converters on the web work the same way: you upload your document to a server, it is processed there, and you download the result and trust that the copy was deleted. For a holiday photo that is a small risk. For a passport scan, a signed contract, a medical report or a bank statement, many people would rather not take it — and they are not always told it is happening.
OneClick Convert was built to remove that trade-off for the tools that can work without it. Most conversions here happen inside your own browser, on your own device. For those tools the file is not uploaded, so there is no server copy to leak, sell or retain. Four optional features do use a server, and they are named below.
The second reason is upload limits. Online forms often state a maximum file size — a form might say “photo under 100 KB” or “PDF under 2 MB”. The limits differ from form to form, so always check the one printed next to the upload field. Many tools give you a quality slider and let you guess; ours searches for the highest quality that still fits under the number you type.
Modern browsers can run compiled code at close to native speed through WebAssembly. Libraries that desktop software uses — a PDF engine, image codecs, the FFmpeg video engine, the Tesseract text-recognition engine — can be compiled to run inside a web page, and this site serves its own copies of them.
When you drop a file onto one of these tools, your browser reads it from your disk, hands it to the engine running in a background thread, and writes the result back out as a download. The file itself is not sent over the network. The page does still talk to our server for other things — loading the engine the first time, anonymous statistics, error reports and advertising — and none of those carry the file or its name. You can check: open your browser’s developer tools, switch to the Network tab, convert a file, and look at what is sent. You can also disconnect from the internet after a tool has loaded and most tools will still work.
The trade-off is worth stating: because the work happens on your device, very large files are limited by your device’s memory rather than by a server. A desktop handles far bigger videos than a phone, and the tools tell you when a file is too large rather than failing silently.
Four features use a server, and each says so before you use it. Speech-to-text transcription: we chose not to run speech recognition in the browser, so the audio goes through our server to OpenAI’s speech-recognition service, and the text to Google’s Gemini for tidying. Converting from a link: a web page cannot download from another site directly, so our server fetches the link for you. Optional download link: if your browser blocks a download, which happens on some iPhone configurations, you can choose to have that one result stored for 24 hours so a normal link can be handed back to you. Smart column detection: in the spreadsheet tool, an optional button sends the column headings and a sample of the rows — never the file name — to Google’s Gemini, through Lovable, to work out what the columns mean.
Every other conversion on this site — PDF, image, spreadsheet, audio and video — runs on your device. The full detail is in our privacy policy.
OneClick Convert is built and maintained by VibeSolutions, an independent studio. It does not sell data, and its business does not depend on your documents.
Every tool is free and the site is paid for by advertising. For a short time in September 2026 it also accepted voluntary contributions; those are closed, and nothing on the site can be bought.
Questions, bug reports and corrections are welcome at support@oneclickconvert.app. See the contact page for what to include.
The interface is available in fifteen languages, including four written right to left — Arabic, Hebrew, Persian and Urdu — and text recognition reads all fifteen. Tool pages and guides are written for each language rather than translated word for word. Arabic needed particular care: in many file tools Arabic text comes out reversed, letters disconnect, or fonts fail to embed in exported PDFs.