Secret Key Generator — Hex & Base64
Generate cryptographic-style secret keys in hex or base64 format at various bit lengths.
How it works
- 1Configure your options above
- 2Click "Generate" — processing happens in your browser
- 3Copy or download the result
What to do next
About Secret Key Generator
Secret Key Generator is a self-contained developer utility workspace. Generate cryptographic-style secret keys in hex or base64 format at various bit lengths. Open the page, get the result, close the tab — that is the entire workflow.
Secret Key Generator is shaped around the recurring needs of two audiences: backend developers inspecting requests, who use it as a quick utility between bigger tools, and devops engineers crafting one-liners, who use it as their primary way of getting the job done. Both groups get the same defaults and the same speed.
Reach for Secret Key Generator when you need a predictable result on a single file. The page works on the first visit, the controls are visible without a menu, and the output is delivered the moment the engine finishes.
Under the hood, Secret Key Generator 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 browser sandbox isolates the page's JavaScript from the rest of the system, the same way it isolates every other tab you have open. Secret Key Generator works inside that sandbox: it reads the file you give it, processes it with standard browser APIs, and writes the result back. Nothing leaves the page's memory unless you choose to download or copy it.
Secret Key Generator is intentionally narrow in what it does, which makes it easy to slot into a longer workflow. Take its output, hand it to whichever next tool fits the job, and Secret Key Generator stays out of your way until the next time you need it.
The hard constraints are easy to remember. Maximum input: 0 MB. Multiple files per run: no — one input at a time, by design, to keep results predictable. The same controls apply on every run.
Secret Key Generator keeps the control set focused. Every option on the page is there because a real workflow needs it, and the defaults aim at the most common case so a first-time user can get the right output without changing any settings.
When the job finishes, Secret Key Generator hands you the result as a sensibly named file. Filenames are derived from your input where possible, so a quick batch of jobs leaves you with a tidy folder rather than a pile of generic "output (3)" files. Nothing is auto-saved on Favtoo's side because nothing was ever sent there.
From a product perspective, Secret Key Generator 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.
Secret Key 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.
If you want to get the most out of Secret Key Generator, three small habits help. Drag-and-drop is faster than the file picker once you get used to it. The keyboard shortcut for downloading the result is whatever your browser uses for "save link as," because the result is a normal download. And if you are working on a sensitive file, processing in an Incognito or Private window is a good extra layer — it leaves no trace in browser history when the tab closes.
If Secret Key Generator 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.
If Secret Key Generator solved your problem, sharing the page link with someone who has the same problem is the most useful thing you can do. The catalog grows mostly through word of mouth; visitors arriving through a recommendation tend to be the ones the tool serves best.
How it works
- 1Land on the Secret Key Generator page. The tool is ready to use the moment the page renders.
- 2Select the developer file you want to process — drag-and-drop and the file picker both work.
- 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
- Compare two API responses to spot a regression using Secret Key Generator.
- Encode binary content for transport in a JSON body.
- Convert between data formats while wiring up an integration.
- Validate a config blob before pushing to staging.
- Pretty-print a minified blob during incident triage.
- Format a noisy log line into something a teammate can read.
- Decode a token to confirm its claims during a debugging session.
- Hash a string for a quick reproducibility check.
- Generate boilerplate from a single specification line.
FAQ
What key sizes are available?
128-bit, 256-bit, and 512-bit keys in hex or base64 format.
Which format should I choose?
Hex for systems expecting hex strings. Base64 for more compact representation.
Can I use these as JWT secrets?
For development yes. For production, use crypto.getRandomValues() or openssl rand.
How many keys can I generate?
Up to 10 keys at once.
Is 256-bit enough?
Yes — 256-bit keys are the standard for AES-256 and most symmetric encryption.
Is data sent to a server?
No — processing happens in your browser.
What permissions does Secret Key Generator need to function?
Secret Key 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.
How is Secret Key Generator different from desktop apps that do the same thing?
Desktop apps usually have more advanced features but require installation, maintenance and (often) a licence. Paid online tools are convenient but route your file through their servers and gate downloads behind accounts. Secret Key Generator sits in between: free, instant, and private, but intentionally narrow in scope. For one-off jobs and the common developer utility operations, it is usually the lowest-friction choice; for highly specialised work, a dedicated app is still the right answer.
How long does Favtoo retain my data after using Secret Key Generator?
Favtoo keeps no copy of your file because Favtoo never receives your file. Secret Key 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.
Does Secret Key Generator work in Safari, Firefox, Chrome and Edge?
Secret Key Generator works in any modern browser released in the last few years — Chrome, Edge, Firefox, Safari, Brave, Arc and the major Chromium derivatives are all supported. The underlying engine relies on widely-supported web APIs, so there is nothing exotic to install. If you are on a very old browser version and the tool fails to load, updating to the latest release of your preferred browser is the only fix needed.
Is there a desktop version of Secret Key Generator?
No installation is needed. Secret Key Generator runs as a normal web page, with no browser extension, no native helper, and no separate desktop client to download. That is partly a privacy choice — extensions can request broad permissions, while a regular page is sandboxed by default — and partly a convenience one: you can use Secret Key Generator on any computer you have temporary access to without leaving anything installed on it.
Where does my file actually go when I use Secret Key Generator?
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.
Is Secret Key Generator mobile-friendly?
Secret Key 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.
Why does Secret Key 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.