Frequently Asked Questions
Q: What is OfflineConverter.com?
A: We are the team behind Aconvert.com, a popular online converter website. While developing Aconvert.com, we noticed some disadvantages of online converters and decided to create an offline converter. Thanks to new technologies such as ES Modules, WebAssembly, Shared Array Buffer, and Site Isolation, it is now possible to convert files offline directly in web browsers. This website was built many years ago, but its release was delayed until most major browsers began supporting these technologies.
Q: Why can files be converted offline in a web browser?A: Files can be converted using JavaScript or WebAssembly in the browser. WebAssembly is a type of code that can be run in modern web browsers - it is a low-level assembly-like language with a compact binary format that runs with near-native performance and provides languages such as C/C++, C#, and Rust with a compilation target so that they can run on the web. It is also designed to run alongside JavaScript, allowing both to work together.
Q: Is OfflineConverter.com secure?A: Yes, OfflineConverter.com is secure to use. As an offline converter-the opposite of an online converter-it offers maximum privacy protection because all files are converted locally on your device rather than on cloud servers. You don't need to worry about your files being leaked. The WebAssembly we use is a safe technology. WebAssembly describes a memory-safe, sandboxed execution environment that may even be implemented inside existing JavaScript virtual machines. When embedded in the web, WebAssembly will enforce the same-origin and permissions security policies of the browser.
Q: How do I convert files on OfflineConverter.com?A: Converting files on OfflineConverter.com is as simple as 1-2-3.
- 1. Click the "Choose Files" button to choose local files from your local device.
- 2. Choose a target format and set conversion options if needed.
- 3. Click the "CONVERT OFFLINE" button and wait for the conversion to complete. The output files will be listed on the same webpage.
A: You can check the supported file formats at https://offlineconverter.com/format/. Please note that this is only a small selection of the formats we support-many less common formats are not listed. For example, OfflineConverter.com supports about 80 image formats, but only the most popular ones are shown. You can convert these less common formats directly without any issues.
Q: Why can't I convert Word, Excel, or PowerPoint to PDF offline on OfflineConverter.com?A: OfflineConverter.com requires converter software that is open-source, small in size, and compatible with compilation into WebAssembly/JavaScript. We use Microsoft Office to convert Word, Excel, and PowerPoint files online on Aconvert.com. Microsoft Office is property software, large in size, and cannot be compiled into WebAssembly/JavaScript.
Q: What platforms and web browsers does OfflineConverter.com support?A: You can use OfflineConverter.com on any operating system (Windows, Linux, macOS, Android, or iOS) that has a modern web browser. Supported browsers include Chrome 57+, Edge 16+, Firefox 52+, Safari 11+, and Opera 44+. Internet Explorer is not supported.
Q: What are the conversion limitations?A: You can select an unlimited number of files at a time. The total file size per webpage can be up to 2 GB. There are no file size limits in Mozilla Firefox.
Q: Why is the first file conversion slow?A: The required JavaScript must be loaded before the first conversion. For video and audio conversions, the JavaScript can be up to 32 MB. It may take some time to download if your internet connection is slow.
Q: Why is the conversion slower compared to desktop software?A: As of now, WebAssembly/Javascript is still a lot slower than native, it is possible to further speed up using WebAssembly intrinsic, which is basically writing assembly code. It is something we are investigating and hope to introduce in the future. Another reason that causes conversion slow is that OfflineConverter.com uses a single thread by default. Using multithread may consume a lot more memory or CPU, and it requires additional security measures such as Shared Array Buffer and Site Isolation.
Q: Why did my conversion fail?A: Most conversion failures are caused by an incompatible web browser or operating system. We recommend updating your OS and browser to the latest version. Other common causes include unsupported, corrupted, password-protected, or DRM-protected source files. Try our online converter instead if this offline converter doesn't work in your web browser.
Q: How can I save all output files in one ZIP file?A: To save all output files in one ZIP file, simply click the "Compress files" button in the "OUTPUT FILES" section.
Q: How can I delete all output files?A: To delete all output files, simply close the webpage in your web browser. All output files will be cleared immediately and cannot be recovered.
Q: Which one should I choose, offline converter or online converter?A: You can check the comparison between offline and online converters on the index page and choose the converter that best suits your needs.
Q: I have more questions. Who should I contact?A: Please send your questions to support@aconvert.com. You will usually receive a reply within one business day for file conversion questions. Other questions may not be answered.