The Email on Acid Insider’s Guide
Everything we know about Email on Acid in one document: what it costs, its grades, getting a refund, getting help and what else to look at. Read it here, or keep a copy.
Email on Acid
The Insider’s Guide
Email previews and pre-send QA, now moving to Mailgun Inspect
Every plan, grade, refund rule and rival among email verification and deliverability tools, read from Email on Acid’s own pages.
Made by Email on Acid · checked Nov 13, 2026 · toolgpa.com
Contents
- 01WelcomeWhat it is, who it suits, its grades and the ten things to know first
- 02What it costsEvery plan, the free plan, ways to pay less and how prices have moved
- 03What it doesIts main features, where it runs, what it works with and who makes it
- 04Where it standsIts grades against its category, and whether to keep it or make your own
- 05The alternativesThe tools it is most often weighed against, side by side
- 06Quick answersThe questions people ask about it, each answered in a line or two
- 07About ToolGPAWho made this guide, what else is on the site, and how to cite it
ToolGPA put this guide together from Email on Acid’s own pages, its app-store listings and our grades. Every fact in it is on Email on Acid’s page too, where it is kept up to date. Checked Nov 13, 2026.
Part 01 · Overview
Welcome
What it is, who it suits, its grades and the ten things to know first
1.8
GPA, above 4 of the 61 other email verification and deliverability tools we grade
Email on Acid previews an email's HTML across 100+ clients and devices before it is sent. Higher plans add accessibility, link, image, code and spam-content checks. The vendor says current customers are moving to Mailgun Inspect, the next-generation product from Mailgun, and that the two are the same line of tools.
To get you started, here are 9 things to know about Email on Acid, taken from its own pages and our grades.
Paste or send the email and read the results, with a migration to Mailgun Inspect under way.
- 1
Best for previewing an email in many clients before a send
Email on Acid shows your email across 100+ clients and devices, with unlimited users and an API.
- 2
Paid plans start at $99 a month
As its pricing page puts it: $99 per month.
- 3
You can try it first
Free trial offered; its length is not stated on the page
- 4
It runs on Web
Web.
- 5
Client and device previews
Each screenshot of a client or device counts as one preview, so a test across 50 clients uses 50 previews.
- 6
Accessibility checks
Premium tests are based on the W3C Web Content Accessibility Guidelines, which the vendor ties to the European Accessibility Act.
- 7
Link and image validation
Premium checks links and images in a message. The FAQ says these checks, unlike previews, are unlimited.
- 8
A 1.8 GPA, above 4 of 61
That is against the other email verification and deliverability tools we grade, on value, the free plan, features, ease of use and platforms.
- 9
Keep it
To replace Email on Acid you would be making newsletters sent to thousands of people that still reach the inbox. That is not a weekend's work, with an AI app builder or without one.
Email on Acid at a glance
- Pricing
- Free trial, from $99 per month
- Free plan
- No
- Free trial
- Free trial offered; its length is not stated on the page
- Runs on
- Web
- Made by
- Email on Acid
- Category
- Email Verification & Deliverability
- Our grade
- 1.8 GPA, weak
The report card
Best for previewing an email in many clients before a send
Email on Acid shows your email across 100+ clients and devices, with unlimited users and an API. Accessibility, spam and link checks only start at Premium, and its pricing page says customers are moving to Mailgun Inspect from June 2026, with old previews not carried over.
| Subject | Grade | Comment |
|---|---|---|
| Value for money | D | Basic is $99 a month for 1,000 previews, above the category's dearer quarter ($49). The checks most people want sit on Premium at $199. |
| Free plan and trial | D | A free trial is offered, but the page states no length. |
| Features | C | Previews, accessibility, link and image checks and spam analysis. It does not send email. |
| Ease of use | C | No rating on record. Paste or send the email and read the results, with a migration to Mailgun Inspect under way. |
| Platforms and integrations | B | Web, with an API and unlimited users on every plan and one listed integration. |
An A is worth 4 points, a B 3, a C 2, a D 1 and an F nothing. The GPA is the average of the five.
Who Email on Acid is for
- Fits if you check each campaign across many email clients
- Works for agencies that need unlimited users on one account
Who it is not for
- Pricey if you add it up, at $99 a month for 1,000 previews
- Skip it if you want accessibility or spam checks on the cheap plan, as they start at Premium, $199
- Watch out: the pricing page says customers move to Mailgun Inspect from June 2026 and old tests are not carried over
- Watch out: it does not send email, so you need a separate sending service
- Watch out: the trial length is not stated
Good to know
Good for
- Email developers testing HTML across many clients
- Marketing teams that need pre-send QA with any email service provider
- Larger teams, since seats are unlimited
Worth knowing
- The pricing page says current customers will move to Mailgun Inspect from June 2026, and that old previews and tests are not carried over.
- Annual-plan customers migrate at the end of their current term.
- Basic has no accessibility, spam or link checks; those start at Premium.
- It does not send email; the FAQ says you need a separate sending service.
Part 02 · Pricing
What it costs
Every plan, the free plan, ways to pay less and how prices have moved
$99
A month to start
Email on Acid is a paid product with a free trial, starting at $99 per month.
A free trial is offered, but the page states no length.
Basic
$99
per month for 1,000 previews
Unlimited users, 100+ preview clients and devices, API access; extra previews cost $0.15 each.
Premium
$199
per month for 2,000 previews
Adds accessibility tests, HTML code analysis, link and image validation and spam content checks.
Contract
Custom
Custom preview allotment with the Premium feature set and phone and chat support; sold through sales.
Trying it first
Free trial offered; its length is not stated on the page
Read from emailonacid.com on Nov 13, 2026.
Part 03 · Features
What it does
Its main features, where it runs, what it works with and who makes it
1
Place it runs: Web
Email previews and pre-send QA, now moving to Mailgun Inspect. Here is what it does, as its own site describes it, and what it covers: public API, reports, email campaigns.
Previews, accessibility, link and image checks and spam analysis.
- Client and device previews
- Each screenshot of a client or device counts as one preview, so a test across 50 clients uses 50 previews.
- Accessibility checks
- Premium tests are based on the W3C Web Content Accessibility Guidelines, which the vendor ties to the European Accessibility Act.
- Link and image validation
- Premium checks links and images in a message. The FAQ says these checks, unlike previews, are unlimited.
- Spam content analysis
- Premium includes content spam checks and HTML code analysis, judged on the message itself and not on your sending reputation.
- API access and unlimited users
- Every plan includes API access, and none of the plans limit how many people on a team can use the account.
Where it runs
- Web
What it works with
- Mailgun
Email on Acid is made by Email on Acid.
Part 04 · Standing
Where it stands
Its grades against its category, and whether to keep it or make your own
4/61
Other email verification and deliverability tools it is graded above
Email on Acid's GPA of 1.8 is higher than 4 of the 61 other email verification and deliverability tools we grade, and level with 3.
It stands best on platforms and integrations (B, above 28 of 61) and worst on value for money (D, above 0).
Its paid plans start at $99 a month, against a middle price of $21.50 for the category: 38 of the 43 others that charge start lower.
On features, ease of use and platforms it scores 2.3 out of 4. 8 tools score higher and cost less.
Each grade against the category
Every bar is all 62 email verification and deliverability tools we grade, cut by the letter each got. Email on Acid’s own letter is outlined.
- DValue for moneyAbove 0 of 61
- DFree plan and trialAbove 6 of 61
- CFeaturesAbove 0 of 61
- CEase of useAbove 2 of 61
- BPlatforms and integrationsAbove 28 of 61
Price against what you get
Each dot is one of 45 email verification and deliverability tools. Further left costs less; higher up scores better on features, ease of use and platforms. Email on Acid is the marked dot.
What paid plans start at, a month (each step along is roughly double) →
Keep it, or make your own?
Whether this is something you could build for yourself with an AI app builder, and what you would give up.
Keep it
To replace Email on Acid you would be making newsletters sent to thousands of people that still reach the inbox. That is not a weekend's work, with an AI app builder or without one.
That makes this kind of software worth paying for, not this one in particular: 54 of the 61 other email verification and deliverability tools grade higher. It costs $1,188 a year.
What you could make
- Reports: an app builder makes this well.
What you could not
- Newsletters sent to thousands of people that still reach the inbox.
- It plugs into other products, Mailgun among them, and has an API.
What this rests on. Email on Acid’s listing: what it does, where it runs, what it plugs into and what it costs. It is a judgement about the kind of software this is. We have not built a replacement for it, and making your own means looking after it too. How we decide, and every tool’s verdict.
Part 05 · Alternatives
The alternatives
The tools it is most often weighed against, side by side
Inbox Monster, GlockApps, MailGenius, Mail-Tester and Validity Engage
The 5 tools Email on Acid is most often weighed against, with where each one differs from it.
- 1.4GPA
Inbox Monster
From $3,750/yr
Email rendering previews and inbox placement testing.
- Inbox Monster also covers dMARC.
- 2.2GPA
GlockApps
Free plan · from $59/mo
Inbox placement testing with DMARC analytics and uptime monitoring.
- GlockApps has a free plan. Email on Acid does not, though it has a free trial.
- Email on Acid also covers reports and email campaigns.
- GlockApps also covers dMARC.
- 2.0GPA
MailGenius
Free plan · from $23/mo
Email spam-score and deliverability tester with DNS checkers.
- MailGenius has a free plan. Email on Acid does not, though it has a free trial.
- Email on Acid also covers reports and email campaigns.
- MailGenius also covers dMARC.
- 2.8GPA
Mail-Tester
Free plan · from $10/mo
Send an email to a test address and get a spam score out of 10.
- Mail-Tester has a free plan. Email on Acid does not, though it has a free trial.
- Email on Acid also covers email campaigns.
- 1.6GPA
Validity Engage
Paid
Inbox placement and sender reputation monitoring for brands.
- Email on Acid also covers reports.
- Validity Engage also covers dMARC.
Part 06 · Questions
Quick answers
The questions people ask about it, each answered in a line or two
13
Questions, each answered in a line or two
The short version of everything above, for when you only need the answer. Each one is told in full in its part of the guide.
Is Email on Acid free?
No, Email on Acid is a paid product, but you can try it first. Free trial offered; its length is not stated on the page.
How much does Email on Acid cost?
Email on Acid lists 3 plans. Basic: $99 per month for 1,000 previews.
What platforms does Email on Acid work on?
Email on Acid is available on Web.
Does Email on Acid have an Android app?
No Android app was listed when its pages were read on Nov 13, 2026. Email on Acid is listed for Web.
Does Email on Acid have an iPhone app?
No iPhone app was listed when its pages were read on Nov 13, 2026. Email on Acid is listed for Web.
Is Email on Acid open source?
Email on Acid is not described as open source on its own site, as read on Nov 13, 2026.
Does Email on Acid have an API?
Yes. Email on Acid offers a public API, according to its own site.
What does Email on Acid integrate with?
Email on Acid's listing names Mailgun. A listing names up to eight integrations, so it may connect to more.
Who makes Email on Acid?
Email on Acid is made by a company of the same name.
What are the alternatives to Email on Acid?
The closest alternatives to Email on Acid in our directory are Inbox Monster, GlockApps, MailGenius, Mail-Tester and Validity Engage.
How does Email on Acid compare with other email verification and deliverability tools?
Email on Acid's GPA of 1.8 is higher than 4 of the 61 other email verification and deliverability tools we grade, and level with 3.
Is Email on Acid good value for money?
ToolGPA grades Email on Acid D for value for money. Its paid plans start at $99 a month, against a middle price of $21.50 for the category: 38 of the 43 others that charge start lower.
Could I make my own version of Email on Acid?
To replace Email on Acid you would be making newsletters sent to thousands of people that still reach the inbox.
Where this guide comes from
The prices, plans, platforms and features were read from Email on Acid’s own pages on Nov 13, 2026, and the grades were given on Nov 13, 2026. Graded from this listing, whose facts were read from Email on Acid's own pages on 13 November 2026. Not based on using the product, and shorter than our full reviews.
Every tool we list gets five grades, A to F, each with its reason, and a GPA that averages them. How each is decided is at toolgpa.com/grades. This guide is ToolGPA’s own work; it is not made, paid for or approved by Email on Acid. Prices change, so check emailonacid.com before you buy.
Part 07 · About
About ToolGPA
Who made this guide, what else is on the site, and how to cite it
7,721
Tools graded, in 95 categories
ToolGPA grades software the way a school report grades a pupil: five subjects, a letter for each with the reason written beside it, and a GPA that averages them. Prices, plans and platforms are read from each maker’s own pages and dated, so you always know how fresh a figure is.
Every grade, review and ranking on ToolGPA is our own judgement. No company can pay for a grade or change one. Every tool on the site has a guide like this one, free to download and pass on. It all lives at toolgpa.com.
7,721
tools graded
95
categories
739
price changes on record
579
apps priced in 12 countries
What else is on toolgpa.com
- Email on Acid, kept up to dateEverything in this guide, with prices and grades as they are todaytoolgpa.com/tools/email-on-acid
- How grades are givenThe rules behind every letter and every GPAtoolgpa.com/grades
- Value chartsWhat each tool costs against what it scores, for every categorytoolgpa.com/charts
- CompareAny two tools side by side, plan by plantoolgpa.com/compare
- Price changesEvery price rise and cut on record, each with its sourcetoolgpa.com/price-changes
- Prices by countryWhat apps cost on the App Store in 12 countriestoolgpa.com/prices-by-country
- Pay lessEvery public discount: yearly billing, students, nonprofitstoolgpa.com/save
- Keep or makeWhich tools are worth paying for, and which you could build yourselftoolgpa.com/keep-or-make
Scan for the live page
Prices and grades as they are today
Quoting this guide?
Please name ToolGPA and link to the live page, so readers can check the figures for themselves:
ToolGPA, "Email on Acid: The Insider's Guide", checked Nov 13, 2026. https://toolgpa.com/tools/email-on-acid
Know someone choosing between email verification and deliverability tools?
Send them this guide: toolgpa.com/tools/email-on-acid/guide
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See our other guides
The best-graded email verification and deliverability tools after Email on Acid, each with an Insider's Guide of its own.
- Email Verification & Deliverability Insider's GuideEvery one of the 63 email verification and deliverability tools we grade, compared
- QuickEmailVerification Insider's GuideBulk email list cleaning and a real-time verification API3.0 GPA
- Mail-Tester Insider's GuideSend an email to a test address and get a spam score out of 102.8 GPA
- Reoon Email Verifier Insider's GuideBulk and real-time email verification with refunds on unknowns2.8 GPA
Choosing software? Every tool graded, every price dated.
Compare tools at toolgpa.com ›Everything in this guide is ToolGPA’s own summary of what Email on Acid’s pages, its app-store listings and public reviews said on the dates shown. Grades are our judgement under the rules at toolgpa.com/grades. Every grade, review and ranking on ToolGPA is our own judgement. No company can pay for a grade or change one. Email on Acid is a trademark of its owner, and this guide is not made, paid for or approved by Email on Acid. Prices and plans change: check emailonacid.com before you buy.