Crypter is a free, open-source file encryption app for macOS that lets you lock any file or folder behind a single strong passphrase — no accounts, no cloud, no subscription required.
What is Crypter?
Crypter is a desktop encryption utility built on AES-256-GCM, one of the strongest symmetric ciphers available today. It wraps that cryptographic muscle in a clean drag-and-drop interface that takes seconds to learn. You pick a file, you set a passphrase, Crypter seals it. That's the whole loop.
The project lives on GitHub and is genuinely open source — you can audit every line of the encryption pipeline yourself, which is more than you can say for most consumer-grade "secure" apps. For anyone who takes the phrase trust but verify seriously, that matters enormously.
What does Crypter do best?
Crypter's greatest strength is its zero-friction workflow: drag a file onto the window, type your passphrase twice, click encrypt. The output is a single .crypto file you can put anywhere — a USB stick, an email attachment, a shared Dropbox folder — and only someone with your passphrase can open it.
I've used it to ship sensitive contract drafts to clients who don't have PGP set up, to lock local backups of API keys and .env files, and to archive old tax documents without worrying about who else might have access to my NAS. In each case the process took under ten seconds. No key management, no certificate infrastructure, no learning curve.
- AES-256-GCM encryption — authenticated encryption catches tampering, not just snooping
- Passphrase-only model — nothing to install on the recipient's side except Crypter itself
- Open source — MIT-licensed, GitHub-hosted, community-auditable
- Works offline entirely — no telemetry, no server handshake, no network required
Is Crypter free?
Yes — Crypter is completely free to download and use. There is no pro tier, no usage cap, and no nag screen. Because it is open source you can also build it from source yourself if you prefer not to use a binary.
Who should use Crypter?
Crypter is the right tool for Mac users who need occasional, practical file-level encryption without committing to a full public-key infrastructure. Developers securing local credential files, freelancers sending sensitive documents to clients, and anyone archiving private records will find it fits naturally into their workflow.
It is not the right tool if you need to encrypt entire disk volumes (use macOS FileVault for that), send encrypted email at scale (look at GPG Suite or Canister), or manage keys across a team (a secrets manager like 1Password Secrets Automation is better suited). Crypter occupies a specific, well-defined niche — one file, one passphrase, one recipient — and it does that niche very well.
How does Crypter compare to alternatives?
The closest macOS alternatives are GPG Suite, Encrypto by MacPaw, and VeraCrypt. GPG Suite is more powerful but demands a solid understanding of public-key cryptography and key servers — the setup friction is real. Encrypto is polished and beginner-friendly but it is a commercial product with a closed-source backend, which is a dealbreaker if you need to audit what's actually happening to your data. VeraCrypt is the gold standard for full-volume encryption but it is dramatically overkill for encrypting a single PDF or folder of API tokens.
Crypter sits in the sweet spot between Encrypto's simplicity and GPG Suite's transparency. It won't replace GPG Suite for email signing or VeraCrypt for whole-disk protection, but for the task of "I need to lock this file and hand it to someone" it is the fastest, most auditable option on macOS.
What are the best Crypter alternatives?
If Crypter doesn't fit your workflow, consider these:
- Encrypto (MacPaw) — friendliest UI, but proprietary and paid for some features
- GPG Suite — public-key cryptography, mandatory for signed email, steeper learning curve
- VeraCrypt — full-volume containers, ideal for multi-gigabyte encrypted vaults
- age — modern CLI alternative to GPG, popular with developers comfortable in the terminal
