A CloudConvert alternative that converts in your browser
People searching this way want to convert a file from one format to another without much ceremony.
Convertto is a file conversion alternative that runs the conversion inside your browser tab instead of on a server. Documents, images, audio, video, archives and data formats are read, converted and written back on your own device, so no file is uploaded, no account is needed, and the only size limit is your machine's memory.
- Where conversion happens
- In the browser tab, using JavaScript and WebAssembly
- Files uploaded
- None for the local tools, which is most of the catalogue
- Account
- Not required, and there is no sign-up
- File size limit
- None imposed by us. Your available memory is the ceiling
- Cost
- Free, with no conversion minutes or credits
What you are looking for, and the tool that does it
| The job | Convertto tool | What it does |
|---|---|---|
| PDF to Word | PDF to Word Converter | Extracts the text and layout of a PDF into an editable .docx |
| Word to PDF | Word to PDF | Renders a .docx to PDF with its formatting intact |
| Image format conversion | Image Converter | Converts between PNG, JPG, WebP and AVIF, in batches |
| Video format conversion | Video Converter | Converts video between MP4, WebM and MKV in the browser |
| Audio format conversion | Audio Converter | Converts audio between MP3, WAV, AAC, OGG and FLAC |
| Excel to CSV | Excel to CSV Converter | Exports Excel sheets to properly quoted CSV |
| Bundling files into an archive | ZIP File Creator | Bundles any number of files into a ZIP archive in the browser |
| Opening an archive | ZIP File Extractor | Looks inside a ZIP, EPUB, DOCX or JAR and extracts the files you pick |
| Ebook conversion | EPUB to PDF Converter | Converts EPUB e-books into printable PDF |
The difference a local conversion makes
A server-side converter has to receive your file before it can work on it. That is a perfectly reasonable architecture, and it is what makes very heavy conversions and format matrices possible. It also means the file leaves your device. For a holiday photo that is irrelevant. For a signed contract, a payslip, a passport scan or a client deliverable under NDA, it is the entire question, and it is usually easier to avoid the transfer than to audit what happens after it.
Convertto's local tools avoid the transfer. The file is read with the File API, processed in a Web Worker, and the result is handed back as a download. You can verify this: open your browser's network panel, run a conversion, and watch that no request carries the file.
Three side effects of working locally
- No upload wait. A 400 MB video starts converting immediately rather than after the upload finishes.
- No queue. There is no shared worker pool to sit behind, because the worker is your CPU.
- No size cap. We impose none. Large files are bounded by the memory the browser will give the tab.
Where a browser genuinely cannot do the job
Heavy media work is also honest about its cost. Video and audio conversion loads an FFmpeg WebAssembly build of roughly 30 MB on first use, which is then cached. That download buys you conversion that never uploads the video itself.
Browsing the catalogue
Converters are spread across PDF tools, image tools, audio and video tools, data and format tools and developer tools. The full tool list shows every one in a single page, and direct format pairs such as PNG to JPG have their own URLs.
Frequently asked questions
Do I need an account to convert a file?
Is there a file size limit?
Are my files uploaded?
Can it convert video?
Does it work offline?
Open a tool
Last updated
Browse all tools