You can edit a subject line in Gmail, but only before you send the message
Gmail does not let you change a subject line after you hit Send. The moment the email leaves your drafts folder, the subject is locked. If you need to alter the subject, you have two options: edit it while the message is still in Drafts, or send a new message with the corrected subject and ask the recipient to disregard the first one.
The most common reason people want to change a subject is that they caught a typo or realized the original subject does not match what they ended up writing. Catching this before you send takes a few seconds. After you send, there is no undo button for the subject line itself.
Key Takeaways
- You can only change a subject line while the email is still in your Drafts folder, before you send it.
- Click the subject line field at the top of the compose window and type over the existing text to change it.
- Once you send an email, the subject line becomes permanent and cannot be edited.
- If you accidentally send an email with the wrong subject, you can send a follow-up message with the correct subject and ask the recipient to refer to the new one.
How to edit the subject line before sending
Open the email in your Drafts folder. Look at the top of the compose window — you will see a field that says "Subject" with your current subject line next to it. Click directly on that text to place your cursor there.
Once the cursor is in the subject field, select all the existing text by pressing Ctrl+A (or Cmd+A on Mac), then type your new subject. You can also click at the beginning or end of the subject and edit it word by word instead of replacing the whole thing. Make your change and then send the email as normal.
If you have already started typing the body of the email and realize the subject is wrong, do not panic — just click back up to the subject field, make your edit, and continue. The compose window stays open until you send, so you have as much time as you need to get it right.
Why Gmail does not let you change subjects after sending
Once an email is sent, it exists in both your Sent folder and in your recipient's inbox. Changing the subject retroactively would create confusion: the recipient would see a different subject in their inbox than what appears in the email thread on your end, or the system would have to update their copy too, which most email services do not do.
Gmail treats the subject line as part of the message metadata — the information that defines the email itself. Once that metadata is written to the server and delivered, it stays the same on both ends. This is true across almost all email providers, not just Gmail.
What to do if you sent an email with the wrong subject
If you realize after sending that the subject line is incorrect or misleading, send a brief follow-up email with the correct subject. In the body, write something like: "Please disregard my previous email with the subject line '[wrong subject]' — I am resending it with the correct subject below." Then paste the content or summarize what you meant to say.
This approach works best when the error is obvious or when the wrong subject might cause real confusion. For minor typos — like "Meting" instead of "Meeting" — most recipients will understand what you meant and a follow-up is not necessary. Use your judgment based on how much the error changes the meaning.
If the email went to many people, a follow-up is more important because some recipients may have already filed or forgotten about the first message. A second email with the correct subject ensures everyone has the right version to reference.
Editing subjects in Gmail on your phone
The Gmail app on Android and iPhone works the same way as the desktop version. Open a draft, tap the subject line field at the top of the compose screen, and edit the text. The subject field is always visible and editable until you send.
On mobile, make sure you are looking at the full compose view, not the quick reply option. If you see a small reply box at the bottom of the screen, tap the arrow or expand button to open the full compose window where you can see and edit the subject.
Common mistakes when changing subjects
The most common mistake is assuming you can edit a subject after sending and then discovering you cannot. Always double-check your subject line before you hit Send — read it out loud if the message is important or going to a professional contact.
Another mistake is leaving the subject line blank by accident. Gmail will warn you and ask if you want to send without a subject, but if you click through without noticing, your email arrives with no subject at all. This makes it harder for the recipient to find your message later. Always fill in a subject that describes what the email is about.
A third mistake is changing the subject of a reply when you should be starting a new email. If you reply to an existing thread but change the subject completely, the email may still appear under the original thread in Gmail's conversation view, which confuses the recipient. For a completely different topic, start a fresh email instead of replying.
Using subject line templates to avoid errors
If you send similar emails often — like status updates, meeting requests, or project reports — consider creating a template. Gmail has a Templates feature that lets you save a compose window with a pre-filled subject and body. When you need to send that type of email again, you can load the template and just fill in the specific details.
To save a template, compose an email with the subject and body you want to reuse. Click the three-dot menu in the compose window, select "Templates," then "Save draft as template." Give it a name. Next time you compose a new email, click the three-dot menu again, go to "Templates," and select the one you want. The subject and body will populate automatically, and you can edit from there.
Frequently Asked Questions
Can I change the subject line of an email someone sent me?
No. You can only change the subject of emails you compose yourself, and only before you send them. If you receive an email with a subject you think is wrong or confusing, you cannot alter it. You can reply with a corrected subject, but the original email keeps its original subject line.
What happens if I change the subject and then save the draft?
The new subject saves with the draft. When you open that draft again later, it will have the updated subject line. You can keep editing the subject and body as many times as you want until you send the email.
If I change the subject, does it affect the email thread?
If you are replying to an existing email and you change the subject significantly, Gmail may treat it as a new conversation instead of part of the original thread. To keep emails grouped together, avoid changing the subject of replies unless you are intentionally starting a new topic.
Can I undo sending an email if I notice the subject is wrong right away?
Gmail has an "Undo Send" feature, but it only works for a few seconds after you click Send — usually around 5 to 30 seconds depending on your settings. If you catch the error within that window, click "Undo" when ready. After that window closes, the email is sent and cannot be recalled.
Why does my subject line look different on my phone than on my computer?
Gmail sometimes truncates long subject lines on mobile devices to fit the screen. The full subject is still there — it just displays shortened. This is a display issue only and does not affect what the recipient sees. They will receive the complete subject line regardless of what device you sent from.