How Our Tools Work | Architecture & Security Overview
Powerful tools. Running on your device.
RunLocalTools is built around a simple idea: useful software shouldn’t require you to upload your files to a server just to get something done.
Our tools are designed to run directly in your browser. That means the actual processing happens on your device rather than on a RunLocalTools processing server.
If you want the short version:
Your browser does the work.
Browse all tools · Read our Privacy Policy · See the Roadmap
What happens when you use a tool?
When you open a RunLocalTools tool, your browser loads the code needed to run it.
When you select a file or enter information, the tool processes that data locally using the capabilities of your browser and device.
For example:
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Images can be manipulated using browser technologies such as Canvas.
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PDFs and documents can be parsed, modified and generated using client-side JavaScript libraries.
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Video and audio tools can use WebAssembly and browser-compatible media libraries for heavier processing.
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Text, developer and data tools can parse, transform and generate content directly in your browser.
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Saved preferences, where supported, can be stored locally in your browser rather than in a RunLocalTools account.
The important distinction is that using a tool does not require sending your working file to a RunLocalTools processing server.
No account required
RunLocalTools doesn’t require you to create an account before using the tools.
There is no subscription tier you need to unlock basic functionality, and there is no requirement to create a profile simply to use a browser tool.
Open a tool, do the work, download the result.
Local processing is the default
Local processing isn’t a privacy mode you have to remember to enable.
It is part of how the tools are built.
That makes RunLocalTools particularly useful for files and information you may not want to upload to an unfamiliar online processing service.
However, local processing doesn’t mean your device is magically risk-free. Your browser, operating system, extensions, network environment and other software on your device still matter. You should always use normal security practices and keep backups of important files.
For more detail about how your information is handled, see our Privacy Policy.
What technologies make this possible?
RunLocalTools uses different browser technologies depending on what a tool needs.
JavaScript
JavaScript handles a large part of the toolkit, from text transformations and calculations to document processing and interface logic.
WebAssembly
Some heavier workloads can use WebAssembly, allowing compiled software libraries to run inside the browser.
This is particularly useful for media-related tasks where ordinary JavaScript alone may not be enough.
Canvas and browser APIs
Image manipulation, drawing, redaction, resizing and other visual operations can be performed using browser APIs such as Canvas.
Client-side libraries
Some tools use established JavaScript libraries to read and generate formats such as PDF, CSV, JSON, Markdown and other structured data.
The library runs as part of the tool in your browser rather than requiring every operation to be sent to a remote processing server.
What about settings and preferences?
Some tools remember preferences such as an export format, interface setting or other configuration.
Where this happens, the preference may be stored in your browser’s local storage.
That is different from storing your files in a RunLocalTools account.
Local browser storage is controlled by your browser and is not an encrypted cloud storage system. On a shared computer, you should treat browser storage accordingly.
What RunLocalTools does not claim
Local processing removes an important category of exposure: your working files do not need to be uploaded to our servers for the tool to process them.
That does not mean RunLocalTools makes blanket claims of legal compliance such as “GDPR compliant” or “HIPAA compliant.”
Compliance depends on the complete environment, policies, contracts, security controls and intended use.
If your organization needs to evaluate the architecture for a particular environment, you can contact us through our Enterprise & Self-Hosted page.
Why we built it this way
A lot of online software follows the same pattern:
Upload → wait for server processing → download.
That can be perfectly appropriate for some applications. But it isn’t necessary for every task.
Many things people need to do with files, text, images, documents and data can be performed directly on their own devices.
That’s what we’re building around.
RunLocalTools is intended to feel less like a collection of disposable “free utilities” and more like a growing software toolkit: useful features, deeper workflows and capable tools without making an account or subscription. We make sure to build around persistence so refreshing tools pages won’t lose your files unless you clear the data, that way you don’t lose progress while you knowingly or unknowingly refreshes.
Feel free to use the “Report A Bug/Feedback” floating buttons on tools to let us know if there is any problems while using anything.
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