SemVer Calculator — Version Bump Calculator
Calculate the next semantic version based on current version and bump type, with npm and git tag commands.
How it works
- 1Enter your values in the fields above
- 2Click "Calculate Version" — all math runs in your browser
- 3View your results instantly
What to do next
About Semantic Version Calculator
Semantic Version Calculator is a developer tool that runs in your browser. Calculate the next semantic version based on current version and bump type, with npm and git tag commands. The page you are reading is the same workspace you will use to do the work: pick a file or paste your input, choose the options that matter to you, and the tool produces the result on your device.
Semantic Version Calculator 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.
Common audiences for Semantic Version Calculator include students learning new languages and engineers debugging API payloads, but plenty of people land on the page through a one-off search and never come back — that is also fine. The tool is built to be useful even when you only ever need it once.
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. Semantic Version Calculator 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.
Most people land on Semantic Version Calculator 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.
When the job finishes, Semantic Version Calculator 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.
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.
If your task needs more than one step, chain Semantic Version Calculator with Git Commit Generator, Changelog Generator, and README Generator. 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.
Semantic Version Calculator 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.
From a product perspective, Semantic Version Calculator 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.
Semantic Version Calculator 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 Semantic Version Calculator: 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 Semantic Version Calculator 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 Semantic Version Calculator 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
- 1Land on the Semantic Version Calculator 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.
- 3Tweak the controls if the defaults are not quite right for your input. The options are kept short and labelled in plain language.
- 4Hit the run button. standard browser APIs does the work in your browser tab.
- 5Grab the output as soon as the run completes. You can also copy the result instead of downloading if the next tool in your workflow accepts pasted input.
- 6Run additional jobs as needed. The same controls and defaults apply on every run.
Common use cases
- Pretty-print a minified blob during incident triage using Semantic Version Calculator.
- Encode binary content for transport in a JSON body.
- Compare two API responses to spot a regression.
- Inspect a regex against a test string before committing it.
- Convert between data formats while wiring up an integration.
- Validate a config blob before pushing to staging.
- Format a noisy log line into something a teammate can read.
- Inspect a payload during local development without writing a script.
FAQ
What is semantic versioning?
A versioning scheme (semver.org) using MAJOR.MINOR.PATCH where major = breaking changes, minor = new features, patch = bug fixes.
What bump types are supported?
Major, minor, patch, and pre-release variants (pre-major, pre-minor, pre-patch) with configurable identifiers.
What commands are generated?
npm version and git tag commands for easy copy-paste into your terminal.
What is a pre-release version?
A version like 2.0.0-alpha.0 indicating a pre-release. Choose alpha, beta, or rc as the identifier.
Can I use v prefix?
The input accepts versions with or without the v prefix (e.g., v1.2.3 or 1.2.3).
Is this calculated locally?
Yes — version calculation runs entirely in your browser.
Is Semantic Version Calculator keyboard accessible?
Semantic Version Calculator 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.
Are jobs run with Semantic Version Calculator stored anywhere?
Favtoo keeps no copy of your file because Favtoo never receives your file. Semantic Version Calculator 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.
How accurate is Semantic Version Calculator?
Semantic Version Calculator 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.
What does Semantic Version Calculator do that command-line tools do not?
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. Semantic Version Calculator 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.
Will Semantic Version Calculator keep working in a year?
Semantic Version Calculator 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 Semantic Version Calculator ask for any browser permissions?
Semantic Version Calculator 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 there any restrictions on using Semantic Version Calculator at work?
Semantic Version Calculator can be used for personal and commercial work alike — there is no separate "business" licence to purchase. The output you generate is yours to use however you want, including in client deliverables, internal documents, or commercial products. Favtoo's only ask is fair, individual use; the tool is not designed to be embedded as a backend service or wrapped behind an API for resale.
What should I do if Semantic Version Calculator fails on my file?
Failures usually fall into one of three buckets: the input is in an unsupported format, the input is over the size cap, or the input is structurally malformed (a truncated download, a partial export, or a stream the engine does not recognise). The first two are easy to confirm — check that your file is in a supported format and that it is below 0 MB. For the third, opening the file in its native viewer first is the fastest way to confirm the source is intact.
Do I need a specific browser to use Semantic Version Calculator?
Semantic Version Calculator 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.