Dead Code Detector — Find Unused Code
Find potentially unused functions and classes by checking if their names appear only once (in the definition) within the file.
How it works
- 1Paste or type your text in the input field
- 2Click "Detect Dead Code" — processing happens in your browser
- 3Copy the result or download as a text file
What to do next
About Dead Code Detector
Dead Code Detector is the kind of utility you bookmark and reach for when you need it. Find potentially unused functions and classes by checking if their names appear only once (in the definition) within the file. It loads quickly, works on any modern browser, and produces a result you can download or copy in a single click.
Dead Code Detector fits naturally into the workflow of devops engineers crafting one-liners and frontend developers prepping fixtures, both of whom typically need a fast result inside the browser. There is no learning curve to budget for: anyone who has used a typical web upload form can complete a run on the first try.
The right moment to reach for Dead Code Detector is when you have a focused developer utility job that fits inside a browser tab. Open the page, drop in the file or paste your input, choose the options that matter, and the tool returns the result.
Under the hood, Dead Code Detector uses standard browser APIs to do the actual work. Input runs through the same engine, with a per-file ceiling of 0 MB so memory usage stays predictable on lower-end laptops and tablets. The engine ships as part of the page bundle, so once the page is loaded the tool keeps working even if your network connection drops.
The execution model is straightforward: your file is bytes in the tab's memory, the engine reads those bytes, computes the result, and hands the result back to the browser. The transformation happens locally, which is why the tool keeps working when your network connection drops mid-job and why it produces the same result every run for the same input.
If your task needs more than one step, chain Dead Code Detector with Duplicate Code Finder, Code Complexity Estimator, and Code Line Counter. Each tool produces output that is a clean input to the next, so multi-step workflows are just a matter of opening the next tool in a new tab and continuing.
A practical note on limits: Dead Code Detector accepts inputs up to 0 MB per run, and the tool processes one input at a time to keep memory usage predictable. If you ever bump into the ceiling, the cause is the size of the input.
Dead Code Detector is built around steady iteration on a small set of options rather than feature creep. Every additional setting attracts a slightly different audience, but a long settings panel makes the common case slower for everyone. The current controls reflect what users of the tool actually use.
Once the engine finishes, the output is offered as an immediate download. There is no preview gate, no email-wall, and no "register to download" intermediary — the file is yours the moment it is ready.
From a product perspective, Dead Code Detector is one of the simplest possible expressions of "do one thing well." The catalog contains dozens of related tools that each handle a slightly different developer utility task, and every one is a separate page rather than a tab inside a larger app. That separation keeps each tool fast to load and easy to bookmark.
Dead Code Detector runs as a regular web page, so there is no install step or permission grant before the first run. The page can be audited by viewing the source or by watching the developer-tools Network tab while a job runs.
Useful patterns when working with Dead Code Detector: keep the input file open in another tab so you can compare against the result; give the output file a descriptive name when saving so you can find it later (the default name is sensible but generic); and treat each run as independent — the tool has no concept of "history", which means you cannot accidentally pollute one job with leftovers from another.
If Dead Code Detector appears to hang, the engine is almost certainly still working — large inputs simply take longer to process inside a browser than they would on a server with multi-core scheduling. For inputs near the 0 MB cap, give it up to a minute on a typical laptop before assuming something is stuck.
That is the whole tool. Use Dead Code Detector for as long as it stays useful to you, and if it does, the catalog has many more tools built the same way. Each applies the same single-purpose discipline, so the way you used this page transfers to the next one you try.
How it works
- 1Open Dead Code Detector in your browser. The page loads quickly and the tool is ready to use the moment it becomes interactive.
- 2Drop a developer file onto the upload area, or click to pick one from your device.
- 3Pick any non-default settings you need. Most users leave the defaults alone for the first run and only revisit if the result needs tuning.
- 4Hit the run button. standard browser APIs does the work in your browser tab.
- 5Download the result. The file is generated in your browser and saved through your normal download flow.
- 6Re-run with different settings as often as you want. Each run produces a fresh output and the original file on disk is never modified.
Common use cases
- Inspect a payload during local development without writing a script using Dead Code Detector.
- Generate a quick fixture without leaving the browser.
- Compare two API responses to spot a regression.
- Format a noisy log line into something a teammate can read.
- Validate a config blob before pushing to staging.
- Pretty-print a minified blob during incident triage.
- Convert between data formats while wiring up an integration.
- Hash a string for a quick reproducibility check.
FAQ
How does detection work?
The tool finds function and class definitions, then checks if the name appears more than once in the file. Single occurrences suggest unused code.
Is this accurate?
It is a basic single-file heuristic. Functions used via imports in other files will show as false positives.
What about exported functions?
Exported functions may be used in other files. The tool flags them if they have no internal references, so review before removing.
Does it handle method calls?
It checks for the name appearing anywhere in the code text. Method calls like obj.method() will be found.
What languages are supported?
JavaScript/TypeScript, Python, and other languages with function/const/class declaration syntax.
Is my code private?
Yes — all analysis runs in your browser with no data uploads.
Is Dead Code Detector mobile-friendly?
Dead Code Detector runs in any modern mobile browser — Safari, Chrome, Firefox and the in-app browsers in most messaging apps all support the underlying APIs. Performance depends on the device: a recent phone handles typical inputs nearly as fast as a laptop, while older devices may take a few seconds longer near the 0 MB ceiling. The interface lays out cleanly on small screens, so you do not need to pinch-zoom to see the controls.
How accessible is the Dead Code Detector interface?
Dead Code Detector uses native HTML controls wherever possible, which means keyboard navigation, focus rings, and screen-reader labels work the way the platform expects. The drop zone accepts files via the keyboard-accessible file picker as well as drag-and-drop, and result downloads use standard browser download flows. If you spot an accessibility gap, Favtoo treats it as a bug worth fixing.
How do I run Dead Code Detector over a folder of files?
Dead Code Detector processes one input at a time by design — it keeps memory usage predictable on lower-end devices and makes results easier to verify. To handle a folder, run the tool once per file; the page stays loaded between runs and remembers your last-used settings, so the second run is essentially instant.
Can I trust the output of Dead Code Detector for important work?
Dead Code Detector is built on standard browser APIs, which is the same class of engine used by professional developer utility pipelines. For deterministic operations, the output is byte-identical to what an equivalent CLI run would produce; for operations involving a codec or a model, the result is well within the range of what comparable tools generate. If you have a specific reference output you need to match, run a small test job first to confirm the configuration produces what you expect.
Which file formats does Dead Code Detector accept?
The accepted formats are listed in the upload area on the tool itself. If your input is in a format that is not directly supported, convert it first using one of Favtoo's converter tools — every Favtoo converter outputs a file that is a clean input to the next tool in the chain.
How often is Dead Code Detector updated?
Dead Code Detector is updated whenever the underlying engine releases an improvement or a bug fix. Because the tool is delivered as a static page, every visit fetches the latest version automatically — there is no "version" to manage on your end. If a particular release ever changes default behaviour, the change is documented on Favtoo's changelog so you can confirm what shifted.
Does Favtoo keep a copy of files I process with Dead Code Detector?
Favtoo keeps no copy of your file because Favtoo never receives your file. Dead Code Detector runs entirely in your browser, the input is held only in your tab's memory, and closing the tab discards it. There is no opt-in cloud history, no "recent jobs" panel synced to an account, and no server-side retention to configure — the architecture simply has nowhere for your file to be stored.