Convert tabs to spaces in Notepad++

indentationnotepadwhitespace

How do I convert tabs to spaces in Notepad++?

I found a webpage that suggests it's possible, but I couldn't find any information about how to do it.

I would like to be able to do that, because some web forms don't respect code with tabs in them.

Best Answer

To convert existing tabs to spaces, press Edit->Blank Operations->TAB to Space.

If in the future you want to enter spaces instead of tab when you press tab key:

Go to Settings->Preferences...->Language (since version 7.1) or Settings->Preferences...->Tab Settings (previous versions)
Check Replace by space
(Optional) You can set the number of spaces to use in place of a Tab by changing the Tab size field.

Related Solutions

Tab key == 4 spaces and auto-indent after curly braces in Vim

As has been pointed out in a couple of other answers, the preferred method now is NOT to use smartindent, but instead use the following (in your .vimrc):

filetype plugin indent on
" show existing tab with 4 spaces width
set tabstop=4
" when indenting with '>', use 4 spaces width
set shiftwidth=4
" On pressing tab, insert 4 spaces
set expandtab

In your [.vimrc:][1] file:
set smartindent set tabstop=4 set shiftwidth=4 set expandtab

The help files take a bit of time to get used to, but the more you read, the better Vim gets:

:help smartindent

Even better, you can embed these settings in your source for portability:

:help auto-setting

To see your current settings:

:set all

As graywh points out in the comments, smartindent has been replaced by cindent which "Works more cleverly", although still mainly for languages with C-like syntax:

:help C-indenting

Eclipse – How to change Eclipse to use spaces instead of tabs

Java Editor

Click Window » Preferences
Expand Java » Code Style
Click Formatter
Click the Edit button
Click the Indentation tab
Under General Settings, set Tab policy to: Spaces only
Click OK ad nauseam to apply the changes.

[Note: If necessary save profile with a new name as the default profile cannot be overwritten.]

Default Text Editor

Before version 3.6:

Window->Preferences->Editors->Text Editors->Insert spaces for tabs

Version 3.6 and later:

Click Window » Preferences
Expand General » Editors
Click Text Editors
Check Insert spaces for tabs
Click OK ad nauseam to apply the changes.

Note that the default text editor is used as the basis for many non-Java editors in Eclipse. It's astonishing that this setting wasn't available until 3.3.

C / C++

Click Window » Preferences
Expand C/C++ » Code Style
Click Formatter
Click the New button to create a new profile, then OK to continue
Click the Indentation tab
Under General Settings, set Tab policy to: Spaces only
Click OK ad nauseam to apply the changes.

HTML

Click Window » Preferences
Expand Web » HTML Files
Click Editor
Under Formatting, select the Indent using spaces radio button
Click OK to apply the changes.

CSS

Follow the same instructions for HTML, but select CSS Files instead of HTML Files.

JSP

By default, JSP files follow the formatting preferences for HTML Files.

XML

XML files spacing is configured in Preferences.

Click Window » Preferences
Expand XML » XML Files
Click Editor
Select Indent using spaces
You can specify the Indentation size if needed: number of spaces to indent.