Superhuman alternative
Stop paying $360 a year
to read your own email.
Superhuman is $30 a month. That's $1,800 over five years, for an app that processes your mail on their servers, with AI that runs on OpenAI's API. Synapse does the same job for €4.99, one time, with AI that runs on your GPU.
No account required · Payment via Gumroad
The 5-year cost
Synapse
€4.99
Total. Forever.
Superhuman
$1,800
$30/mo × 60 months
Real-time email, without the cloud
Superhuman syncs your email through their servers. That's how their "read receipts", AI insights, and snooze reminders work: your mail passes through their infrastructure. Synapse connects directly to Gmail via the native API or to any IMAP server via IDLE push. No relay. No read receipts for Superhuman's product team. Your mail goes from Google's servers to your machine. Full stop.
AI on your GPU, not OpenAI's
Superhuman's AI features send your email content to OpenAI to generate replies and summaries. Synapse runs Qwen3.5-4B locally on your Vulkan GPU. Your drafts, your summaries, your action items. None of it ever leaves your machine. Enable it once from Settings → AI with a ~2.5 GB one-time download, then it runs offline forever.
Search that works offline
Superhuman's search is cloud-indexed. It doesn't work without a connection. Synapse runs hybrid full-text and semantic search locally. Type 'budget Q2' and find the email that says 'financial projections for the second quarter', because Synapse understands meaning, not just keywords. All of it runs on your machine, in milliseconds, with no API call.
You own it
If Superhuman raises prices, pivots, or shuts down, you lose access. That's the deal with subscriptions. Synapse is a one-time purchase. Your email data lives on your machine. Even if I stop shipping updates, the app keeps working and your data stays yours.
Lifetime access · All future updates included
Email done right
- Gmail REST API + IMAP IDLE push for all other providers, no polling
- Thread view with expandable conversations and newest-first toggle
- Bulk actions: move, delete, archive, mark read with keyboard support
- One-click unsubscribe from any mailing list
- Open .eml attachments inline without leaving your inbox
- Italian PEC certified email (S/MIME auto-extracted)
- OAuth2 for Google and Microsoft, password never stored
Search that actually works
- Gmail-style query DSL: from:, subject:, is:unread, has:attachment and more
- BM25 full-text + 768-dim multilingual semantic search, 100+ languages
- Smart reranker: keyword score, semantic similarity, recency, personal history
- Search inside attachments and nested .eml files
- Saved searches, history, and contact autocomplete typeahead
AI without the cloud
- On-device AI assistant (Qwen3.5-4B, Vulkan GPU)
- Local model: 0 bytes to OpenAI. Or BYOK your own key.
- Grammar-constrained plugin output: structured JSON, no hallucinated fields
- Auto low-memory mode on machines with 16 GB RAM or less
Privacy you can verify
- TPM-sealed AES-256 credential vault
- Offline-first SQLite, all data stays on your machine
- 0 telemetry, 0 analytics, 0 cloud relay
What else you get
- Asana · ClickUp · Calendar · Reminders plugins
- 28 themes across light, dark, half-dark, and aurora variants
- Gmail-style and Mailbird-style keyboard shortcut presets
- Multi-language spellcheck in compose
- Built-in address book
- Automatic Ed25519-signed updates, no manual downloads