How we make this list: we compare pricing pages, product documentation and public user reviews. Ratings come from G2, Capterra or Trustpilot, with the date we checked them.
Key takeaways
- Shortwave is the strongest Spark swap for Gmail users who want more AI search and drafting.
- Superhuman Mail is the speed option, at a premium price and only for Gmail and Outlook accounts.
- Canary Mail keeps AI and security features on device and starts at $36 a year.
- Apple Mail and Outlook are free and already installed for most people, with growing AI features.
- Proton Mail and Thunderbird are the privacy exits, one hosted and encrypted, one free and open source.
Quick comparison
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The best Spark alternatives in 2026
Starting price$18/month
Free planYes
Shortwave is what Spark users on Gmail usually try first when the draw is AI. Built by former Google staff, it treats your archive as searchable knowledge: ask for the contract a client mentioned last spring and it finds the thread rather than a keyword match. Its assistant drafts replies in your voice and splits the inbox into useful piles automatically.
The hard limit is accounts. Shortwave works with Gmail and Google Workspace only, so anyone juggling iCloud, Yahoo or a private IMAP server, all of which Spark handles happily, cannot use it as their only client. The Pro plan is $18 per seat a month, with Business at $30. For a Gmail only life, it is the most capable swap here.
What we like- Natural language search reaches across years of Gmail history, AI assistant drafts, summarises and sorts inside the client, bundles and filters tame newsletters and notifications, free plan covers light AI use with 90 days of search
Watch out for- Gmail and Google Workspace accounts only, free plan stamps outgoing mail with its signature, deeper AI and longer history sit in pricier tiers up to $120 a month
Starting price$25/month
Free planNo
Superhuman Mail, now part of the Superhuman company formed around Grammarly, sells one thing: speed. Every action has a shortcut, the inbox splits by sender type, and recent plans add AI that labels, drafts and answers questions about your mail. People who live in email for hours a day routinely call it the fastest client they have used.
The price keeps it a niche choice. Starter runs $30 per user a month, or $25 a month billed yearly at $300, and Business rises to $40. There is no free plan, and it connects only to Gmail and Outlook. If email is a small part of your day, Spark or a free client below does the job for nothing. If it is most of your day, the arithmetic can still favour Superhuman.
What we like- Keyboard first design processes heavy inboxes faster than any rival, split inboxes and auto labels sort mail before you see it, read statuses and snippets speed up follow ups, AI drafts in your voice on the Business plan
Watch out for- No free plan, Starter is $30 a month or $25 billed yearly, Gmail and Outlook accounts only, price is hard to justify for light email users
#3Canary Mail
Best for: Privacy controls across all platforms4.5/5 on
G2 (53 reviews, checked Oct 2026)
Visit canarymail.io
Starting price$36/year
Free planYes
Canary Mail is the privacy minded all rounder. It covers the four main platforms, supports PGP encryption, adds read tracking protection, and offers AI help with summarising and drafting while keeping its privacy posture clearer than most rivals. The maker publishes this list's source comparison itself, so treat its ranking of its own product with the caution any vendor list deserves.
Growth costs $36 a year, which undercuts Spark's paid tiers while covering more platforms than Shortwave or Superhuman. The free plan is usable rather than a demo, with unlimited accounts across two devices. For a Spark user whose concern is where their mail data goes, Canary is the natural first test.
What we like- Encryption support with PGP built in, AI features run with privacy controls rather than a mandatory cloud account, runs on Mac, Windows, iPhone and Android, free plan allows unlimited accounts on two devices
Watch out for- Full AI Copilot sits in the paid Growth plan, interface is less polished than Spark or Superhuman, team features are thinner than dedicated shared inbox tools
Starting priceFree
Free planYes
Apple Mail is the alternative most Spark users already own. It handles Gmail, Outlook, iCloud and IMAP accounts, syncs across Apple devices, and has gained summaries, categories and priority messages through Apple Intelligence on recent hardware. For a single user on Apple kit, the gap to Spark has narrowed a lot.
What it still lacks is opinion. Spark and Shortwave actively sort and draft for you; Apple Mail mostly presents your mail well and leaves the work to you. There is no Windows or Android version and never will be. If your accounts and devices are all Apple and your inbox is manageable, the free incumbent is hard to argue with.
What we like- Already installed on every Mac and iPhone at no cost, Apple Intelligence adds summaries and priority sorting on newer hardware, strong privacy features including mail privacy protection, no third party account between you and your mail provider
Watch out for- Apple devices only, organisation features lag Spark and Shortwave, search across very large archives can feel slow, no real team or shared inbox features
#5Microsoft Outlook
Best for: Microsoft 365 and Exchange accounts4.5/5 on
G2 (3,547 reviews, checked Oct 2026)
Visit outlook.com
Starting priceFree
Free planYes
Outlook is the default answer for anyone whose mail lives in Microsoft 365. The apps are free on Mac, Windows, phones and web, the calendar and mail share one home, and Exchange support is native rather than bolted on. For a Spark user moving into a Microsoft workplace, it removes a layer rather than adding one.
The annoyances are real but minor: ads in free mobile apps for some accounts, a busy interface, and the best AI locked behind Copilot licences that cost more than Spark ever did. None of that matters much when the alternative is fighting a third party client against an employer's Exchange policies. In Microsoft shops, Outlook is the pragmatic swap.
What we like- Free apps on every platform including web, the natural home for Microsoft 365 and Exchange mail, focused inbox, scheduling and calendar in one place, Copilot features on business plans add drafting and summaries
Watch out for- Advertising appears in the free mobile apps for some users, interface density puts off minimalists, AI features worth having sit behind Microsoft 365 Copilot pricing, personal and work account handling can confuse
Starting price$3.99/month
Free planYes
Proton Mail is the structural privacy exit. Where Spark, Shortwave and Superhuman all process your mail on their servers to power smart features, Proton encrypts mail so the provider cannot read it, and offers a free plan to start. Mail Plus costs $3.99 a month billed yearly and adds storage, addresses and filters.
The trade is intelligence for secrecy. Encrypted mail cannot be searched or summarised the way Gmail based AI clients do it, and moving years of mail across takes patience. For journalists, lawyers and anyone whose threat model is real rather than theoretical, that trade is the entire point, and no other entry here offers it.
What we like- End to end encryption for mail between Proton users, free plan with a real inbox rather than a trial, based in Switzerland with a strong published privacy record, bridge app lets desktop clients work with the encrypted account
Watch out for- Search is limited by encryption compared with Gmail based clients, importing large archives takes time, using your own other clients requires the bridge, AI drafting features are minimal beside Shortwave or Superhuman
#7Thunderbird
Best for: Free open source mail on any desktop4.3/5 on
G2 (340 reviews, checked Oct 2026)
Visit thunderbird.net
Starting priceFree
Free planYes
Thunderbird, the long running open source client from the Mozilla family, is the free option that asks nothing of you: no subscription, no account with the maker, no server side processing of your mail. It runs everywhere including Linux, handles any IMAP or POP account, and its add on ecosystem covers most features the paid clients advertise.
It looks and feels its age, and there is no built in AI assistant drafting your replies. In exchange you get the only client on this list whose incentives are simply to be good mail software. For Linux users, the privacy cautious and anyone tired of subscriptions, Thunderbird remains the sensible default.
What we like- Completely free and open source with no account or tracking, runs on Windows, Mac and Linux where Spark cannot, huge add on library for encryption, filtering and calendar, you keep full local control of your mail data
Watch out for- Interface feels dated beside modern clients, AI features only arrive through third party add ons, setup for multiple accounts is manual compared with Spark, mobile apps are newer and less mature
How we chose
This list reads Spark as Spark Mail the email client, the common meaning of the keyword, and the introduction states that reading. Alternatives were chosen to cover the real reasons Spark users leave: stronger AI on Gmail, speed, privacy, platform gaps such as Linux, team use, and free incumbents. Prices come from vendor pages and October 2026 trackers and are stated with their billing period, because annual and monthly figures are not comparable. Superhuman's ownership change under the Superhuman company is noted in its entry. Where a source is a vendor's own comparison, the entry says so. Spark is the reference point and is not listed as its own alternative.
What to check before you switch email clients
Check your accounts first, because they rule out half this list. Gmail only tools cannot see your iCloud or IMAP mail, and encrypted Proton Mail changes how search and other apps reach your messages. Write down every account you actually read weekly and test the new client against all of them, not just the biggest.
Then test the workflow, not the feature list. Process three real days of mail in the new client: triage in the morning, search for an old thread, draft a reply you would normally write. You will know by day two whether the AI help is worth its price or whether the free incumbent was enough. Finally, remember a client swap does not move your mail; your messages stay with your provider, so switching back is cheap. That makes email the lowest risk category in software to experiment with.
Frequently asked questions
Is Spark on this list the email app or Apache Spark?
The email app, Spark Mail by Readdle. The keyword almost always means the email client in consumer searches, and every alternative here is an email client. Apache Spark is a data processing engine with a completely different set of rivals.
Which Spark alternative is best if I only use Gmail?
Shortwave, for its AI search and drafting built specifically around Gmail and Google Workspace. Superhuman Mail is the other strong Gmail option if speed matters more than price.
What is the best free Spark alternative?
Apple Mail on Apple devices and Thunderbird everywhere else cost nothing and carry no subscription. Shortwave and Canary Mail have free plans with limits if you want AI features without paying.
Does switching clients move or delete my email?
No. A client is a window onto your account with Gmail, Outlook, iCloud or your own server. Your mail stays with the provider, and you can run two clients side by side while you decide.
Which alternative keeps my mail most private?
Proton Mail, because mail is encrypted so the provider cannot read it. Thunderbird is the other strong answer: it processes mail locally on your machine and sends nothing to a client maker's servers.
Sources we checked (0)
Is your product missing or out of date?
We review this list regularly. Vendors can request a listing, send updated pricing or ask about featured placement.
Shihab Mia · Founder, Rankite
Shihab has 5+ years in B2B and SaaS SEO. He writes Rankite's software buying guides from pricing pages, documentation and public user reviews. More about Shihab.
Shortwave
Superhuman Mail
Apple Mail
Proton Mail