Semver Bumper
Bump a semantic version by major, minor, patch or prerelease and get the next valid version.
What is Semver Bumper?
A semantic version calculator. Enter a version and a release type and it returns the next version according to the semver specification and the behaviour of npm version, including the rules for prereleases.
How it works
The version is parsed strictly into major, minor, patch, prerelease and build parts. A plain bump increments the relevant part and clears the lower ones; a pre* release starts or advances a prerelease with the identifier you choose; and bumping major or minor on an existing prerelease releases it (1.0.0-rc.1 becomes 1.0.0) rather than jumping a whole version. Every non-obvious decision is explained under the result.
- Paste or fill in the input. Drop in a commit message, a diff, a package.json, a path list or a set of options. The tool reads it locally — nothing is uploaded and no repository is contacted.
- Adjust the rules to match your project. Every linter here takes its convention from a setting you can change: allowed commit types, header length, target branch length, known branch names. Set them once to what your team actually uses.
- Copy the result. Generated files copy straight to the clipboard or download as a real file with the right name (.gitignore, CODEOWNERS, LICENSE, COMMIT_EDITMSG), and Reset returns every field to its default.
Examples
A commit message that fails CI
"Updated(auth): Fixed the expired-token redirect." is rejected by release automation and reported here with the exact reasons: unknown type, capitalised description, past tense and a trailing period.
A .gitignore that only half works
The Checker shows which rule decides a path — and why `!keep.txt` inside an ignored directory never fires, the mistake that sends people to Stack Overflow.
A dependency bump nobody reviewed
The package.json Diff separates added, removed and changed entries per section, so a caret bump of a runtime dependency does not hide inside a lockfile-sized pull request.
A diff pasted from a code review comment
The Diff Viewer understands several `diff --git` blocks, mode-only changes, renames and binary stubs, and calls out a pasted `--stat` summary instead of rendering an empty box.
Common mistakes
Committing a .gitignore without checking it
Rules look right and behave differently: a pattern containing a slash is anchored to the root, a trailing slash means directories only, and a file inside an ignored directory cannot be re-included. Check the paths that matter before you commit the file.
Rewriting published history
A clean commit history is worth having, but amend, rebase and filter-repo change commit hashes. Only rewrite commits that nobody has pulled; after a rewrite, push with --force-with-lease rather than --force.
Treating a generated file as if it were reviewed
These tools produce a starting point, not a decision. Check the licence text against the canonical source, read the security policy before publishing it, and make sure a CODEOWNERS team actually exists — GitHub silently ignores rules whose owner has no write access.
Putting slow checks in a pre-commit hook
A hook that takes 30 seconds gets bypassed with --no-verify within a week, and then it protects nothing. Keep pre-commit to formatting and linting, move type checks and tests to pre-push or CI.
Frequently asked questions
Why is 1.0.0-rc.1 bumped to 1.0.0 by `major`?
Because that is what npm version does: a prerelease of x.0.0 is a preview of x.0.0, so releasing it keeps the number. Only a prerelease whose minor or patch is non-zero is treated as a preview of the next major.
When do I use premajor instead of major?
When you want to publish a preview of the next major without claiming it: 1.4.2 → premajor gives 2.0.0-alpha.0, which installs only when someone asks for the prerelease explicitly.
Does the tool touch my package.json or create a Git tag?
No. It only computes the next version and shows you the equivalent npm version command — nothing is written and no repository is contacted.