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Subject Line Checker

Chrome extension by sendgoodemails.com · Productivity · Tools

A Chrome extension in Productivity · Tools with 16 users, barely installed.

No site access is declared in the manifest, so it cannot read the pages you open on its own.

What the developer says, and 4 screenshots

Loading from the Chrome Web Store. Open the listing if it does not appear.

Users
16
Rating
5.0 (1 ratings)
Users, last 12 days
+1
Rating, last 30 days
Not watched long enough to say
Version
1.0
Updated in the store
2026-04-21
Published
2026-04-21
Manifest
V3
Browser access
1 permission

How it has moved

Users
+1 since 01.09
15-17 · 6 readings
  1. 2026-09-0115
  2. 2026-09-0516
  3. 2026-09-0616
  4. 2026-09-0817
  5. 2026-09-1016
  6. 2026-09-1216
Rating
unchanged since 01.09
reviewsrating 5.00 · 6 readings
  1. 2026-09-01reviews1rating5.00
  2. 2026-09-05reviews1rating5.00
  3. 2026-09-06reviews1rating5.00
  4. 2026-09-08reviews1rating5.00
  5. 2026-09-10reviews1rating5.00
  6. 2026-09-12reviews1rating5.00
Users
+1 since 01.09
15-17 · 6 readings
  1. 2026-09-0115
  2. 2026-09-0516
  3. 2026-09-0616
  4. 2026-09-0817
  5. 2026-09-1016
  6. 2026-09-1216
Rating
unchanged since 01.09
reviewsrating 5.00 · 6 readings
  1. 2026-09-01reviews1rating5.00
  2. 2026-09-05reviews1rating5.00
  3. 2026-09-06reviews1rating5.00
  4. 2026-09-08reviews1rating5.00
  5. 2026-09-10reviews1rating5.00
  6. 2026-09-12reviews1rating5.00

A dot marks a day the store showed a different number. Between them the line carries the last one forward: we read every listing more than once a day and record a point only when something moves. History beyond ninety days is in the app.

What it can reach

No site access is declared in the manifest, so it cannot read the pages you open on its own.

  • Act on the current tab, but only after you click it activeTab

The full permission history for this extension

What changed recently

Nothing has moved on this listing since we started watching it.

The publisher

sendgoodemails.com.

Like this one

Listings the catalog judges closest in what they say they do.

  1. Email Characters Describes nearly the same job, smaller audience 205 users ★ 3.0
  2. Unbury Subject Line Checker Describes nearly the same job 0 users
  3. Email Testing & Email Preview - Inbox Pirates Describes nearly the same job, smaller audience 676 users ★ 5.0
  4. Email Device Preview & AI Summary Tool Describes nearly the same job, smaller audience 80 users ★ 5.0
  5. Subject Line Ruler by Loop Describes nearly the same job, smaller audience 324 users ★ 5.0

The top 5 only. The full comparison, with why each one is close, is on the alternatives page; ranking a whole neighbourhood by your own criteria is in the app.

Is this your extension?

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Figures come from our own daily pass over the public Chrome Web Store listing, last read on . We publish no contact details for extension developers.