Mock Data Generator — Fake Data for Testing
Generate realistic mock data for users, products, posts, companies, or addresses in JSON or CSV format.
How it works
- 1Configure your options above
- 2Click "Generate Mock Data" — processing happens in your browser
- 3Copy or download the result
What to do next
About Mock Data Generator
Mock Data Generator is shaped around how people actually use developer utility utilities online: open the page, drop in a file, get the result. Generate realistic mock data for users, products, posts, companies, or addresses in JSON or CSV format. The interface stays out of the way once the work begins so the engine can use the available CPU and memory for the actual transformation.
Mock Data Generator runs on standard browser APIs — an open-source, well-audited engine that performs the developer utility natively in the browser. It accepts the formats listed in the upload area and produces output that opens in any standard developer viewer. Per-run input is capped at 0 MB.
Most people land on Mock Data Generator via a search at the moment they actually need the tool. That shapes the design: the page is a single screen with the input on one side, the controls in the middle, and the result on the other, so a first-time visitor can complete the job without reading documentation.
The architecture is local-first by design. Once the page is loaded, you can disconnect from the network and the tool still completes the job. The processing stack — standard browser APIs and the small UI shell wrapping it — ships with the page itself, so the tool keeps working in offline conditions, on a captive-portal Wi-Fi, or behind a corporate proxy that limits what the tab can reach.
The architecture imposes only the limits the browser itself imposes. The published 0 MB ceiling is conservative; most modern devices comfortably handle inputs up to that size, and the cap exists so the tool degrades gracefully on phones and budget laptops rather than running out of memory.
If your task needs more than one step, chain Mock Data Generator with Fake Data Generator (SQL), TypeScript Interface Generator, and JSON Validator. 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.
Mock Data Generator sees the most use from engineers debugging API payloads and frontend developers prepping fixtures, but the design is intentionally generic enough that you do not need a specialist background to get a good result. The defaults aim at the most common case so a first-time user can get the right output without changing any settings.
Output handling is intentionally boring: Mock Data Generator produces a single output file and triggers your browser's standard "save" behaviour. If you have a default download folder configured, that is where it will land. There is no Favtoo-side history of jobs you have run.
Some notes on the design of Mock Data Generator. The page is intentionally narrow: one input, the controls relevant to the task, and one output. Adding unrelated features would make the common case slower for the majority of users, so the surface is held to what people actually use.
Mock Data Generator is structured around the idea that a useful tool should be its own page. Open the page, do the work, close the tab — the page is the entire product. There is no onboarding flow because there is nothing to onboard into.
Pro tip: Mock Data Generator works just as well in a private/incognito window as in a normal one, which is occasionally useful when you want zero browser-history footprint of the job. Another tip: if the tool ever feels slow, it is almost always because the browser tab is competing for CPU with another tab — pausing or closing the heavy ones gives the engine room to work.
Mock Data Generator 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.
When something goes wrong, the cause is usually one of three things: a malformed input, a browser that is out of memory, or a corporate proxy that is interfering with the page's static assets. The first two are easy to diagnose; the third typically requires asking your IT team to allow standard browser APIs to load.
That is the whole tool. Use Mock Data Generator 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 Mock Data Generator in your browser. The page loads quickly and the tool is ready to use the moment it becomes interactive.
- 2Select the developer file you want to process — drag-and-drop and the file picker both work.
- 3Adjust the options to match what you need. Sensible defaults cover the most common case, so you can usually skip this step.
- 4Trigger processing. standard browser APIs reads your input, applies the transformation, and writes the result back into the page.
- 5Download the result. The file is generated in your browser and saved through your normal download flow.
- 6Repeat the process for additional inputs whenever you need to. The page stays loaded, so subsequent runs are quick.
Common use cases
- Inspect a regex against a test string before committing it using Mock Data Generator.
- Format a noisy log line into something a teammate can read.
- Convert between data formats while wiring up an integration.
- Encode binary content for transport in a JSON body.
- Compare two API responses to spot a regression.
- Hash a string for a quick reproducibility check.
- Pretty-print a minified blob during incident triage.
- Validate a config blob before pushing to staging.
FAQ
What data types are available?
Users (name, email, age, role), Products (name, price, category), Posts (title, author, tags), Companies, and Addresses.
How many records can I generate?
Up to 100 records per generation. Run multiple times for larger datasets.
What output formats are supported?
JSON (formatted with indentation) and CSV with automatic header generation.
Is the data random?
Yes — names, emails, and other fields are randomly combined from curated word pools for realistic-looking results.
Can I customize the fields?
Currently the fields are predefined per data type. For custom fields, use the Fake Data Generator (SQL) tool.
Is data generated locally?
Yes — all data is generated in your browser with no server calls.
Does Mock Data Generator ask for any browser permissions?
Mock Data Generator only needs the standard web platform — file picker access for the inputs you choose to load, and optionally clipboard access if you copy the result rather than downloading it. There is no microphone, camera, geolocation or background-permission request, because none of those are needed for the work the tool does.
Are jobs run with Mock Data Generator stored anywhere?
Favtoo keeps no copy of your file because Favtoo never receives your file. Mock Data Generator 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.
Why does Mock Data Generator feel slow on large inputs?
Most jobs finish in seconds. Speed scales with input size and with how many CPU cycles your browser tab has available — the engine runs in your browser, so it shares resources with whatever else you have open. For inputs near the 0 MB ceiling, expect anywhere from a few seconds to roughly a minute on a typical laptop. Closing other heavy tabs noticeably speeds things up.
Can I self-host Mock Data Generator for my team?
Mock Data Generator is a static page running an open-source engine in your browser, so a typical corporate firewall does not get in the way as long as it allows JavaScript to load from Favtoo. For teams that need to host it themselves on an internal network, the underlying engine (standard browser APIs) is open-source and can be packaged into a private build with the same behaviour. Reach out via the Contact page if that is something you are exploring.
Will Mock Data Generator keep working if my Wi-Fi drops mid-task?
Once the page is loaded, Mock Data Generator can complete jobs without an active internet connection — the engine is bundled with the page, so there is no per-job network call. The initial page load does require a connection (to fetch the static assets), but after that you can disconnect entirely and the tool will still work. This is a side-effect of the local-first architecture, not a deliberate "offline mode" feature.
Does Mock Data Generator work on a phone or tablet?
Mock Data Generator 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 often is Mock Data Generator updated?
Mock Data Generator 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.
Is it safe to use Mock Data Generator on confidential files?
Your file is processed inside your browser by standard browser APIs. The engine reads the file's bytes from your tab's memory, computes the result, and writes the result back into the tab. You can confirm what the page does by opening developer tools and watching the Network tab during a run — the requests you see are for the tool's static assets only.