Apollo.io
ZoomInfo
Lusha
Hunter.io
Instantly.ai
Clearbit
Snov.io
lemlist
SYNCDATE
OneCal.io
Calensync
ChronoLink
SyncThemCalendars
Multical
CalendarBridge
SyncGene
SYNCDATE is a web application for live two-way Google Calendar synchronization. Connect multiple Google accounts, select which calendars to sync, choose direction (one-way or two-way), and SYNCDATE keeps events aligned automatically in the background.
Built for professionals juggling multiple Google calendars across work, personal, and side-project accounts.
Outlook support with cross-provider sync - coming soon.
Apollo.io SYNCDATENo SYNCDATE videos yet. You could help us improve this page by suggesting one.
SYNCDATE's answer:
SYNCDATE treats sync as silent infrastructure โ it shows proof instead of making promises. Every sync run is logged with stats, every error comes with a deterministic fix step, and every sync can be cleanly reversed with optional event cleanup. Most calendar sync tools are black boxes. SYNCDATE exposes sync health, freshness, and latency so you can verify it's working in seconds, not just hope it is.
SYNCDATE's answer:
A generous free-forever tier (2 accounts, 2 calendars) covers the most common use case at zero cost โ competitors start at $4โ12/mo. Privacy is the default: synced events show as "busy" unless you opt in to detailed copying. And if you ever want to stop, the Clean Exit flow removes all SYNCDATE-created events from your calendars โ no orphaned copies left behind.
SYNCDATE's answer:
SYNCDATE's answer:
SYNCDATE was born from a real problem: juggling multiple Google accounts and constantly getting double-booked because calendars didn't talk to each other. Existing tools were either expensive for what they offered, opaque about what they were doing, or left orphaned events behind when you stopped using them. SYNCDATE was built to be the sync tool we wanted โ minimal, transparent, and safe to turn off.
SYNCDATE's answer:
Next.js (App Router) with TypeScript, PostgreSQL via Drizzle ORM, Redis with BullMQ for background job processing, Google Calendar API with webhook push notifications, and Stripe for billing. Deployed on a Hetzner server behind Cloudflare with a standalone Node.js worker for sync execution. Observability stack uses Grafana, Loki, Prometheus with PagerDuty for alerts.
We use Apollo with our Sales and BDR team to manage our cold outreach. The strength of the platform is the sequences and cadences that you can set up. Compared to other tools we have used in the past like Salesloft the UI is much easier to navigate. The main limitation is that the quality of data isn't as vast and often I can find prospects on Linkedin but not in Apollo.
Based on our record, Apollo.io seems to be more popular. It has been mentiond 69 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
Personal email domains destroy this. Clearbit's Enrichment API returns a null company when it hits gmail.com. Apollo routes personal domains straight to a consumer bucket and skips B2B fields entirely. Even PDL's /person/enrich endpoint โ the most permissive of the major providers โ gives you around 32% hit rate on Gmail addresses versus 74% on corporate domains. I measured this across 6,200 signups for a... - Source: dev.to / about 1 month ago
A few things worth flagging: PDL beats Clearbit's historical rates for US and Western European companies, but drops to ~52% match rate for Japan and South Korea specifically. Apollo underperforms on raw company matching but returns significantly more contacts per domain in Prospector-style queries than Clearbit's Prospector ever did โ the tradeoff is more stale titles in the result set. Hunter.io is fast and cheap... - Source: dev.to / about 1 month ago
One thing comparison guides consistently get wrong: Clay is not an enrichment API. It's a waterfall orchestration tool that calls People Data Labs, Apollo, Clearbit, and others in sequence for you. It's useful, but it adds 2โ8 seconds of latency per row in my runs and costs more per match than going direct. For a CRM webhook flow where you need sub-second enrichment calls, Clay is the wrong layer to hit first. - Source: dev.to / 2 months ago
Last year I ran the same LinkedIn Sales Navigator export through three enrichment APIs. Apollo matched 61% of the emails. Hunter.io matched 54%. An OSINT-first pipeline I'd built in n8n โ pulling from public sources before hitting any paid API โ matched 79% and cost roughly $0.003 per contact. The delta wasn't magic. It was sequence. - Source: dev.to / 2 months ago
Despite having its LinkedIn Page removed in 2025, Apollo remains a functional enrichment and outreach platform with 275M+ contacts. The free tier includes 10,000 credits and the $49/month basic plan is the cheapest entry point for a combined enrichment-plus-sequencing workflow. Apollo's data collection methods have attracted LinkedIn's attention, but the product continues to operate. The risk I'd assign it:... - Source: dev.to / 2 months ago
ZoomInfo - ZoomInfo is a B2B database providing detailed business information on people and companies.
OneCal.io - Sync Outlook and Google Calendars in real-time, share booking links, and view all your calendars in one view.
Lusha - Search less. Sell more.
Calensync - Synchronize your Google, Outlook, and iCalendars instantly, and create scheduling links to easily book events based on your availability
Hunter.io - Find all the email addresses related to a domain
ChronoLink - Flexibly synchronize events between different calendars. Select and transform events according to your rules. Supports Google, Microsoft (Outlook.com / Exchange Online), Exchange Server, iCalendar/ICS and other systems.