Where does processing occur?
Inside the browser, using Web Workers, Tree-sitter parsers, and the local Rust/WebAssembly comparison engine.
Privacy and security boundary
Private code comparison that runs in your browser
AlignDiff’s comparison flow parses, pairs, and diffs source text locally in the browser. This page states the current boundary precisely, including what browser-local processing does not protect against.
Direct answers
What happens to the code you paste
Is source code transmitted to AlignDiff?
The comparison flow does not upload the pasted source code to an AlignDiff server. It is also not executed.
Can site analytics see the source?
The current application does not include an analytics script, and source text is not placed in page URLs. Normal hosting requests can still expose request metadata such as IP address, user agent, and requested page—not the pasted comparison text.
Are comparisons stored?
There are no accounts or saved comparisons in the current beta. Comparison text is held in page memory and is lost when the page is reloaded or closed.
Security limitations
Browser-local does not mean risk-free
- A compromised browser, extension, device, or copied clipboard can still expose source code.
- The application is a public beta and has not been presented as independently security-audited.
- Very sensitive or regulated code may require an organisation-approved offline tool and security review.
- Do not paste credentials, tokens, private keys, production data, or other secrets into any comparison tool.
Local comparison path
From pasted text to aligned result
1Text areasOld and new source remain in the page.
2Web WorkerParsing and comparison run away from the main UI thread.
3Tree-sitter + Rust/WASMStructures are extracted, paired, and diffed locally.
4Rendered resultOnly the browser displays the paired comparison.
Evaluate the claim
Use browser developer tools for your own check
Open the Network panel, paste a non-sensitive sample, run a comparison, and inspect requests. This gives your team direct evidence for the deployed version it is evaluating.
Continue exploring