Best AI Tools for Cold Email Outreach

Cold email is not dead. But the version that worked in 2019 is. The spray-and-pray era collapsed under the weight of Google’s 2024 authentication mandates, tightened spam thresholds, and inbox algorithms that now weigh reading time and reply quality rather than just click rates. What has replaced it is something far more precise: AI-driven outreach where machines handle research, personalization, sequencing, and reply management while humans focus on positioning and deal strategy.

This guide covers every major AI-powered cold email tool in 2026, with real benchmarks, pricing breakdowns, verified user data, head-to-head comparisons, and a final matchup so you know exactly where to put your budget.

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Why Cold Email in 2026 Is a Different Game

Before you pick a tool, you need to understand the environment these tools operate in.

Average cold email open rates have stabilized at 27.7% in 2026, down from roughly 36% in 2023, while platform-wide reply rates now average 3.43%, down from 5.1%, reflecting continued inbox competition and tighter spam filtering. Martal Group

The overall average reply rate is 3.43%, but top-performing campaigns from elite teams exceed 10% reply rates, which is 2-4x higher than average. 58% of all replies are generated from step one in a cold email campaign, and the remaining follow-ups contribute 42% of total replies, proving that follow-up persistence can improve campaign results. Instantly

Personalization is the biggest single lever: emails tailored to recipients see a 32% higher response rate, while customized subject lines improve open rates by 50%. Campaign size also matters significantly; smaller, targeted campaigns with 50 recipients or fewer average a 5.8% response rate, compared to 2.1% for larger, untargeted lists. Mailforge

Timeline-based email hooks outperform problem-statement hooks by 2.3x in reply rates and 3.4x in meetings booked across all industries and ICP roles. Research from Hunter.io’s analysis of 11 million emails confirms that personalization depth drives 52% higher reply rates, and smaller, highly-targeted campaigns outperform broad blasts by 2.76x. The Digital Bloom

AI agents now handle roughly 80% of research and sequencing work for elite cold email teams, freeing humans to focus on positioning, messaging strategy, and high-value conversations. The question has shifted from “how many emails?” to “how precisely can we target?” Instantly

The deliverability floor also changed permanently. Around 17% of cold emails never reach the inbox, often due to poor domain authentication, high bounce rates, or spam-triggering language, making technical setup mission-critical. Gmail’s enforced spam complaint threshold is 0.1%, and exceeding it risks filtering or permanent rejection. Martal Group

Outreach that combines email with LinkedIn and phone in a coordinated omnichannel sequence can boost results by over 287% compared to email-only sequences. Martal Group

These numbers frame every tool decision that follows.

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Industry Reply Rate Benchmarks (2026)

Source: Snov.io Cold Email Statistics 2026, compiled from platform-wide campaign data.

C-level executives respond 23% more often than non-C-suite employees, with reply rates of 6.4%. Mailforge

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The Core Categories of AI Cold Email Tools

Tools in this space fall into three functional categories, and conflating them causes teams to overspend or underperform:

1. Sending and deliverability platforms (Instantly, Smartlead, Woodpecker)
2. Prospecting, enrichment, and data platforms (Apollo, Clay, Snov.io, Hunter)
3. Full-stack sales engagement platforms (Reply.io, Lemlist, Saleshandy, Klenty)

The strongest stacks in 2026 pair a data enrichment layer with a sending layer. Very few tools do both well at scale, and pricing reflects the gaps.

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Tool-by-Tool Breakdown

1. Instantly.ai

Instantly is the platform most teams encounter first when searching for cold email tools at scale. Over 50,000 sales teams have adopted Instantly for inbox placement, response rates, and deal generation, with documented cases of users sending over 100,000 emails across 20 or more domains at 20%+ reply rates. Instantly

What it does well: Unlimited mailboxes, AI Copilot for sequence writing, inbox placement testing, a 450M+ verified B2B lead database on higher-tier plans, and an AI Reply Agent that triages and responds to incoming emails in under 5 minutes.

Sales teams using sub-5-minute reply automation report 3x higher meeting booking rates compared to 30-minute manual response times. Instantly

Deliverability: Instantly runs warm-up via a pool of 200,000+ real accounts. The setup is fast and requires minimal technical knowledge. However, some users have reported emails landing in spam despite being warmed up, especially with new Gmail accounts, and the warm-up system may not fully comply with Google’s updated 2026 security guidelines. Sparkle

Best for: Agencies, solo founders, and sales teams that want to move fast, scale volume, and manage everything from one dashboard without a developer on the team.

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2. Smartlead.ai

Smartlead is a robust cold emailing platform trusted by over 31,000 businesses. It handles email deliverability, lead generation, cold email automation, and sales outreach, with unlimited mailboxes, AI warmup functionality, a multi-channel infrastructure, and a unified inbox. Smartlead

Where Instantly prioritizes simplicity, Smartlead prioritizes technical control. It uses dynamic IP rotating, ESP matching, real-time AI learning that refines deliverability strategy without manual adjustments, and a dedicated spam rescue tab.

What it does well: The strongest deliverability engine in its price bracket, white-label support for agencies, advanced inbox rotation, and native integrations with HubSpot, Salesforce, Pipedrive, Clay, and Zapier.

What it lacks: Smartlead does not include a native lead database. You import contacts from external tools like Apollo, Hunter, or Clay. For technical users who already have data pipelines, this is not a blocker. For sales leaders who want one system, it adds friction. Instantly

Smartlead is the better choice for agencies and power users who want granular control, but expect a steeper learning curve upfront. Sparkle Agency white-labeling is available but adds $29 per client per month.

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3. Apollo.io

Apollo occupies a unique position because it leads with data rather than deliverability. Apollo is a cold outreach platform that offers a large database of B2B leads, along with automation and AI for sales outreach across multiple channels. Its AI features include an AI-powered Outbound Copilot that researches prospects, finds and categorizes leads, crafts tailored messages, and automates cold email outreach, along with AI lead scoring that ranks prospects based on engagement, fit, and buying signals. Snovio

Apollo dominates for data-first teams thanks to its 275M+ contact database, though its outreach tools are secondary. Hypergen

Key limitation: Apollo’s sending infrastructure was not built for the deliverability demands of 2026 high-volume cold outreach. Apollo gives you amazing prospect data, then leaves you scrambling when your emails hit spam folders because their deliverability infrastructure can’t handle volume. Salesforge Most serious cold email teams use Apollo for prospecting and pipe those leads into Instantly or Smartlead for sending.

Free plan: Apollo offers a forever-free tier with 100 credits per month, making it accessible for evaluation.

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4. Clay.com

Clay is not a cold email sending tool. It is a data enrichment and workflow automation platform that sits upstream of your sending tool, and it is one of the most powerful things to happen to outbound in the last three years.

Clay aggregates multiple data providers and uses a waterfall approach: if Provider A doesn’t have the email, it tries Provider B, then C. This typically yields 20-40% higher match rates compared to single-provider tools. MarketBetter Blog

Clay’s Claygent is an AI research agent that can scrape publicly available web data to find office locations, founder backgrounds, recent news, job postings, and company initiatives, then use that context to generate personalized email openers. The businesses achieving 8-15% reply rates on cold outbound in 2026 are doing hyper-personalized outreach at scale where every email looks like it was written specifically for that recipient, and Clay is the platform that has made this possible at any business size. Echelon-advising

Critical limitation: Clay does not run full cold email campaigns. For sequencing, inbox rotation, and tracking replies, you still need tools like Instantly, Smartlead, or Mailshake. Lindy

Clay’s subscription price covers roughly 40-60% of the real cost of running Clay at scale. Adding Sales Navigator, an email sequencer, and a CRM puts the true cost significantly higher. Derrick App

Credit burn warning: Clay charges credits for failed lookups. If you query three providers searching for an email address and none return a result, you pay for all three attempts. On pipelines with stale or incomplete data, this miss rate can silently burn 20-30% of your monthly allocation. Derrick App

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5. Lemlist

Lemlist differentiates itself through personalization formats that no other tool matches. It supports personalized images, GIFs, and dynamic landing pages inside cold emails, alongside LinkedIn automation and WhatsApp outreach (as a paid add-on).

Lemlist is a sales outreach platform designed for cold email teams that prioritize personalization, visuals, and multichannel reach. It takes a creative approach with personalized visuals to enhance the recipient’s experience. However, users can connect only three email accounts for sending on the base plan, and new users may be overwhelmed by its complex user interface. SalesHandy

The main knock against Lemlist is its per-seat pricing model. Lemlist’s per-seat pricing at $69 per user per month makes scaling expensive Instantly relative to flat-fee alternatives. For agencies managing multiple clients, this compounds quickly.

Best for: B2B teams targeting high-value, low-volume prospects where a creative, personalized approach justifies the extra cost per contact. Not the right tool for volume-heavy campaigns.

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6. Reply.io

Reply.io is an AI-powered platform rated 4.6/5 on G2 with over 1,300 reviews that helps sales reps take cold outreach to the next level by combining AI automation with multi-channel sequences. It has access to over 1 billion verified B2B contacts and over 60 million company records. SalesHandy

Its standout feature is Jason AI, an AI assistant that generates personalized email sequences, handles responses, and books meetings autonomously based on user prompts, recipient profiles, and campaign goals.

Reply.io is a powerful all-in-one sales engagement platform that consolidates a B2B contact database, multichannel sequencing, AI-powered writing tools, and appointment scheduling into a single system. ColdIQ

Pricing note: Reply.io charges per slot rather than per seat, where one slot equals one email account. This model is more expensive at low volumes but competitive once you scale across multiple accounts.

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7. Saleshandy

Saleshandy is the best choice for high-volume senders like agencies and sales teams scaling outreach with AI automation, an 830M+ B2B database, built-in CRM, and unlimited accounts starting at $25 per month. SalesHandy

Saleshandy is an AI-assisted cold outreach platform rated 4.6/5 on G2 with over 650 reviews. Its AI Sequence CoPilot generates a multi-step sequence from just a few prompts about the target or offer, auto-personalizing at each stage. SalesHandy

Saleshandy is one of the few tools where unlimited email accounts, email warmup, a large B2B database, and basic CRM functionality coexist at a startup-accessible price point. The tradeoff is that it lacks the visual personalization depth of Lemlist and the raw deliverability engineering of Smartlead.

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8. Woodpecker

Woodpecker is for teams that prioritize safety over speed. Woodpecker is best for small teams that want a simple, deliverability-focused tool with condition-based campaigns, and it maintains the strongest reputation for deliverability through human-like sending patterns and advanced testing capabilities. SalesHandy

It generates lower volume than Instantly or Smartlead by design, using behavioral sending logic that mimics human patterns. Cold email teams that have burned domains and want to rebuild credibility while staying active often migrate to Woodpecker for a cycle before returning to higher-volume platforms.

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9. Klenty

Klenty merges email, phone, SMS, and WhatsApp into one workflow. Its AI assistant, Ask Kai, writes sequence copy based on CRM data and web research. The system includes power and parallel dialers so reps can alternate between calls and digital follow-ups without switching tools. Real-time analytics show call volume, reply quality, and cadence performance in one view. 11X

Klenty sits in a narrow niche: SDR teams running coordinated email-plus-phone motions that need a single analytics layer across both channels. It is not a fit for pure cold email volume plays.

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10. Snov.io

Snov.io is a robust lead generation and outreach automation platform that combines cold email automation with prospecting and sales engagement features. Paid options start at $39 per month. Snovio It covers email finding, verification, drip campaign sequencing, and basic CRM all in one system, which makes it one of the most complete entry-level tools for small teams that do not want to manage a multi-tool stack.

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Comprehensive Pricing Table (2026)

Apollo organization plan: $149/user/month with a 3-user minimum. For a 5-person SDR team, that is $745/month before any add-ons.

Clay true cost: At the Pro tier ($720/month annual), the effective cost per enriched lead is approximately $0.16. Add a Sales Navigator subscription at $99/user/month, an email sequencer at $37-137/month, and a CRM, and a 5-person team can spend $800-2,000+ per month on the full stack.

For agencies managing 10 or more clients, Instantly saves $290+ monthly compared to Smartlead because it offers unlimited client inboxes without per-client fees, while Smartlead charges $29 per client for white-labeling. Instantly

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In-Depth Pricing Analysis: What You Actually Pay

The sticker price for cold email tools is almost always misleading. Here is what teams discover after 90 days of use:

Instantly: The $30/month Growth plan covers 5,000 emails/month. At that volume for an agency sending 50,000 emails/month, you need the Hypergrowth plan at $77.6/month (annual). The dedicated lead database and AI Reply Agent are locked behind higher tiers. The CRM add-on is an additional $47/month on top of the sending plan, and dedicated IP rotation only unlocks at $358/month. SalesHandy

Smartlead: Base price of $33/month covers 2,000 active leads. The pricing structure scales by active lead count rather than users, which is favorable for agencies running large lists. At $174/month you get 30,000 active leads with full API access and white-label features, making the cost-per-lead economics strong at scale.

Apollo: Per-seat pricing means each new hire adds to your bill immediately. A 10-person SDR team on the Basic plan ($49/user) pays $490/month for limited sending capability. The Professional plan at $79/user/month gets you to $790/month and still lacks the high-volume sending that dedicated tools offer.

Clay: The Starter plan at $149/month results in a cost of approximately $0.75/lead for basic enrichment, which is a significant premium. The Pro plan at $720/month is where unit economics genuinely work, at roughly $0.16 per fully enriched lead with AI personalization included. Derrick App Clay also recently introduced a new pricing structure with Launch ($185/month) and Growth ($495/month) tiers that consolidate CRM integrations and web intent signals at lower price points than before.

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Head-to-Head Comparisons

Instantly vs Smartlead: Deliverability Showdown

Both offer unlimited mailboxes and automated warmup. The practical differences emerge at scale.

Instantly makes warm-up easy to set up. You connect your email and the tool starts simulating real conversations using a pool of 200,000+ real accounts. Warm-up stats and inbox placement are visible in a clean dashboard, and even non-technical users can follow along. Sparkle

Smartlead uses unique IP rotating for each campaign and dynamic ESP matching that adjusts in real time based on deliverability signals. Its spam rescue tab monitors spam rates against the strict Google and Yahoo 0.3% spam complaint threshold.

Performance comparison from real campaigns: In direct tests, Smartlead’s deliverability engine is more adaptive over time. Instantly is faster to set up and wins on ease-of-use. Smartlead wins on raw infrastructure for teams sending 30,000+ emails monthly across multiple domains.

Agency economics: Smartlead is great for agencies and power users who want granular control. Instantly is better for solo users or small teams wanting to get started without a steep learning curve. Sparkle

Verdict: Instantly for teams under 10,000 emails/month or those without a technical co-pilot. Smartlead for agencies and high-volume senders who want full control over deliverability levers.

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Apollo vs Clay: Data Layer Comparison

These tools are often compared because they both sit upstream of the sending platform, but they solve different problems.

Apollo is a complete prospecting suite with a 275M+ contact database, built-in sequence execution, intent data filters, a Chrome extension for LinkedIn prospecting, and a native dialer. Clay has no database of its own but aggregates 150+ external data sources through waterfall enrichment.

Clay’s waterfall approach typically yields 20-40% higher data match rates than any single provider, but aggregating sources means some return outdated data, and users report getting personal emails instead of work emails or job titles that are one to two years old. MarketBetter Blog

Apollo excels for teams that want one login for prospecting, sequencing, and reporting. Clay excels for RevOps teams that need maximum data coverage and AI-powered personalization at the enrichment layer before sending in a dedicated tool.

Cost reality: For a 5-person team, Apollo at $49/user/month costs $245/month with full database access and sequencing included. Clay at the Explorer tier ($349/month) adds $99/month for Sales Navigator per user, plus a sending tool, potentially putting total stack cost above $900/month.

Verdict: Apollo for all-in-one simplicity. Clay for teams willing to invest in a more complex stack where hyper-personalization is the primary competitive lever.

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Lemlist vs Saleshandy: Personalization vs Volume

Lemlist differentiates on creative personalization depth, including custom images and video. Saleshandy differentiates on database size (830M+) and flat-fee pricing that includes unlimited accounts.

For high-value account-based outreach where a single deal is worth $20,000+, Lemlist’s visual personalization justifies the cost premium. For volume-driven outreach across broad ICPs, Saleshandy’s economics are superior and the AI Sequence CoPilot reduces manual work.

Verdict: Lemlist for enterprise-targeted campaigns. Saleshandy for growth teams that need to scale volume affordably.

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Matchup and Winner by Use Case

Best for High-Volume Agency Sending

Winner: Smartlead Unlimited mailboxes, flat-rate agency pricing, white-label features, and the most sophisticated deliverability infrastructure at scale. Agencies managing 10+ client domains will benefit from its ESP matching, IP rotation, and spam rescue capabilities.

Best for All-in-One (Prospecting + Sending)

Winner: Instantly (combined with its native lead database on higher plans) For sales teams who need data, sending, AI reply handling, and CRM in one subscription, Instantly wins on cost per meeting and operational simplicity. Instantly The AI Reply Agent alone saves hours of manual response work per week.

Best for Data-Led Hyper-Personalization

Winner: Clay + Instantly stack Clay handles research, enrichment, and AI-generated personalized openers. Instantly handles warm-up, rotation, and deliverability. Teams that invest in this combination are the ones achieving 8-15% reply rates on cold outbound in 2026, running outreach where every email looks like it was written specifically for that recipient. Echelon-advising

Best for Small Teams on a Budget

Winner: Saleshandy Starting at $25/month with unlimited accounts, an 830M+ database, and an AI Sequence CoPilot, Saleshandy offers the most complete feature set at the lowest entry price. It is not the most sophisticated tool in any single dimension, but the depth-to-dollar ratio is unmatched.

Best for Multichannel (Email + LinkedIn + Phone)

Winner: Reply.io A 1B+ verified contact database, Jason AI for autonomous follow-up, native LinkedIn sequence steps, and a built-in dialer make Reply.io the strongest option for teams running coordinated multichannel cadences. It carries a higher per-user cost, but the consolidation reduces the need for additional tools.

Best for Enterprise Prospecting Data

Winner: Apollo.io Intent filters, technographic data, a 275M+ database, buying signal tracking, and an AI Outbound Copilot make Apollo the default choice for enterprise SDR teams. The deliverability limitations are real, but pairing Apollo for prospecting with a dedicated sending platform solves that gap.

Best for Deliverability-Obsessed Teams

Winner: Woodpecker Behavioral sending patterns, human-like timing delays, and advanced inbox placement testing. Woodpecker trades volume for safety and is the right tool for teams that have been burned by domain reputation damage and need to rebuild.

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What the Numbers Say About AI in Cold Email Right Now

B2B buyers now demand personalization similar to what they receive as consumers, with 75% expecting tailored experiences by 2026, according to Forrester Research. 11X

Personalized cold emails deliver positive ROI for nearly 9 in 10 sales teams, and 81% of sales and marketing decision-makers engage with cold outreach when it is tailored to their company or context. Sopro

Campaigns with advanced personalization beyond first name saw reply rates up to 18%, double the average of generic templates. Only 5% of senders personalize every message, yet those see 2-3x the replies of standard campaigns. Martal Group

Sending two to three follow-up emails starting three days after the initial message can increase response rates by up to 65.8%. The first follow-up can boost replies by 49%, while the second adds another 3%. A third follow-up sees diminishing returns, with effectiveness dropping by about 30%. Mailforge

The Belkins 2025 benchmark found that the first follow-up gets an 8.4% reply rate at peak, but by the fifth follow-up it drops to 3.8%. After four or more follow-ups, you triple your spam and unsubscribe risk. Yourmarketingbowl

Tuesday achieves the highest cold email open rate at 46.9%, but Wednesday generates the highest reply rate at 2.6%. This disconnect makes sense: Tuesday emails get opened because it is the least hectic weekday, but Wednesday emails generate replies because recipients have had time to process and respond. Coldmailopenrate

Mailboxes that discontinue warm-up entirely after reaching target volume see a gradual decline in open rates of approximately 8-12% over 60 days. Maintaining 5-10 warm-up emails per day indefinitely preserves inbox placement. Coldmailopenrate

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The Technical Non-Negotiables in 2026

No AI tool overcomes a broken sending infrastructure. These are the baseline requirements before any tool delivers results:

SPF, DKIM, and DMARC authentication are now enforced at the ESP rejection level following Google’s 2024 mandate, not just filtered. Any domain without proper authentication will fail delivery at scale.

Healthy cold email programs trend below 2% bounce rates and keep spam complaints under 0.3%. Cap daily sends per inbox at 30 during ramp-up and increase gradually to protect domain reputation. Instantly

Agencies sending 30,000 or more emails monthly across multiple client domains require 10 or more rotated domains regardless of platform choice, because scaling to that volume on a single domain will destroy inbox placement rates. Growleads

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Recent News and Market Shifts

The email warmup tool market generated $200 million in revenue in 2024 and is projected to reach $600 million by 2033, driven almost entirely by the need to build sender reputation in increasingly hostile inbox environments.

Clay updated its pricing structure in early 2026, consolidating its three self-serve plans into two new tiers (Launch and Growth) and separating data credits from workflow actions. The change makes CRM integrations available at $495/month instead of the previous $800/month Pro threshold. Existing customers can stay on legacy pricing until April 10, 2026.

Landbase emerged from stealth in September 2024 with $12.5 million in seed funding from A*, 8VC, and First Minute Capital, pioneering what it calls the first agentic AI platform for go-to-market execution. Landbase Agentic AI platforms that operate autonomously across channels are the direction the market is clearly moving, with the goal of reducing human involvement in research and sequencing to near zero while improving targeting precision.

The days of a single tool handling everything are narrowing. The dominant pattern among high-performing teams in 2026 is a three-layer stack: a data enrichment tool for building and researching lists, a dedicated sending platform for deliverability at scale, and an AI layer for personalization and reply management. The exact combination depends on deal size, team size, and whether you are optimizing for volume or precision.

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Final Recommendation Summary

If you are starting out or running a small team: Saleshandy or Instantly on the Growth plan. Both offer flat-fee pricing, unlimited accounts, and enough AI tooling to compete without a large budget.

If you are an agency managing multiple clients: Smartlead for deliverability control and white-label economics. Add Clay if you want to build a personalization moat.

If you need the best database and are willing to use a separate sender: Apollo for prospecting, piped into Instantly or Smartlead for sending.

If multichannel outreach is the strategy: Reply.io for its Jason AI, 1B+ database, and native LinkedIn sequence support.

If hyper-personalization is your primary differentiator: Clay plus Instantly is the combination that the highest-performing outbound teams are running in 2026. The setup cost is higher, but the reply rates justify it for any deal size above $5,000.

Cold email works in 2026. It just requires better infrastructure, tighter targeting, and AI doing the work that humans used to spend hours on. The tools to do all of that exist today.