Instantly
Instantly is an automated cold email outreach platform that helps you scale your lead generation through unlimited email accounts, automated warmups, and a searchable B2B contact database.
Email on Acid
Email on Acid is a comprehensive email pre-deployment platform providing automated testing, content checking, and deliverability tools to ensure your campaigns look perfect across all major inbox providers.
Quick Comparison
| Feature | Instantly | Email on Acid |
|---|---|---|
| Website | instantly.ai | sinch.com |
| Pricing Model | Subscription | Subscription |
| Starting Price | $37/month | $74/month |
| FREE Trial | ✘ No free trial | ✓ 7 days free trial |
| Free Plan | ✘ No free plan | ✘ No free plan |
| Product Demo | ✓ Request demo here | ✓ Request demo here |
| Deployment | ||
| Integrations | ||
| Target Users | ||
| Target Industries | ||
| Customer Count | 0 | 0 |
| Founded Year | 2021 | 2009 |
| Headquarters | New York, USA | San Antonio, USA |
Overview
Instantly
Instantly helps you scale your cold email outreach without worrying about deliverability or account limits. Instead of paying per email address, you can connect unlimited sender accounts to a single subscription, allowing you to distribute your volume and keep your primary domain safe. You can automate the entire process from lead sourcing to personalized sequences and follow-ups.
The platform solves the common headache of emails landing in spam by providing automated account warmup and smart deliverability features. You can manage all your replies in a centralized Unibox, ensuring you never miss a lead. Whether you are a solo founder or a large lead generation agency, the system provides the infrastructure to send thousands of personalized emails daily while maintaining a human touch.
Email on Acid
Email on Acid helps you eliminate the guesswork of email marketing by previewing your campaigns across over 100 different email clients and devices. You can catch rendering issues, broken links, and accessibility problems before you hit send, ensuring every subscriber has a consistent experience. The platform automates the tedious manual testing process, allowing your team to deploy high-quality emails faster and with more confidence.
Beyond simple previews, you can optimize your inbox placement with deliverability tools that check your IP against blacklists and validate your SPF and DKIM records. Whether you are a solo developer or part of a large enterprise marketing team, the platform provides the technical insights needed to bypass spam filters and improve engagement. You can integrate these checks directly into your existing workflow to maintain brand standards across every communication.
Overview
Instantly Features
- Unlimited Email Accounts Connect as many sender accounts as you need without paying extra per seat so you can scale your volume safely.
- Automated Email Warmup Improve your sender reputation automatically by joining a network of real accounts that interact with your emails to prevent spam.
- B2B Lead Finder Access a database of over 160 million verified contacts to find your ideal customers and add them directly to your campaigns.
- Centralized Unibox Manage every reply from every connected email account in one single dashboard so you can respond to leads faster.
- Campaign Personalization Use dynamic variables and AI-driven attributes to make every automated email feel like a personal message written just for the recipient.
- Advanced Analytics Track your open rates, click rates, and reply rates across all campaigns to see exactly what is driving your sales.
Email on Acid Features
- Unlimited Email Previews. View your email exactly as it appears on 100+ combinations of devices and clients to ensure perfect rendering every time.
- Campaign Precheck. Run an automated checklist to verify links, images, and accessibility standards so you never miss a critical error.
- Spam Testing. Test your emails against 23 different spam filters to identify potential delivery issues before they impact your open rates.
- Email Editor. Make real-time code changes in a live editor and see instant updates across all previews without re-uploading your files.
- Accessibility Checks. Optimize your emails for screen readers and visually impaired subscribers with automated ADA compliance suggestions and color contrast adjustments.
- Image Validation. Check for missing alt text and optimize file sizes to ensure your images load quickly and convey meaning effectively.
Pricing Comparison
Instantly Pricing
- Unlimited sending accounts
- Unlimited email warmup
- Up to 5,000 emails per month
- Up to 1,000 active leads
- Advanced multi-step campaigns
- Everything in Growth, plus:
- Up to 100,000 emails per month
- Up to 25,000 active leads
- Premium support
- Advanced sequence options
- Unibox for centralized replies
Email on Acid Pricing
- 1 user seat
- Unlimited email previews
- Campaign Precheck
- Email editor
- Accessibility testing
- Standard support
- Everything in Basics, plus:
- 3 user seats
- Spam testing
- Deliverability insights
- Advanced analytics
- Priority support
Pros & Cons
Instantly
Pros
- Unlimited email accounts provide massive cost savings
- Automated warmup significantly improves inbox placement rates
- Centralized Unibox makes managing multiple accounts easy
- Interface is clean and very easy to navigate
- Lead finder database is integrated directly into the workflow
Cons
- Lead database credits can be expensive to replenish
- Learning curve for setting up custom tracking domains
- Customer support response times can vary during peaks
Email on Acid
Pros
- Unlimited testing allows for frequent iterations without extra costs
- Fast rendering speeds for quick campaign turnarounds
- Comprehensive accessibility tools ensure inclusive marketing
- Intuitive interface makes it easy for non-technical users
Cons
- Higher starting price point than some basic competitors
- Spam testing is restricted to higher-tier plans
- Occasional lag when loading a large number of previews