EmEditor Professional is a text editor for Windows used for code, log files, CSV data and files too large for ordinary editors. It combines everyday editing with a table view for delimited data, line filtering, batch search and replace, scriptable macros and plug-ins. Professional is the paid edition and starts with a trial. When the trial ends, the program drops to the EmEditor Free edition instead of stopping. Both editions use the same executable, and the Help menu switches between them.
Opening very large files
EmEditor runs as a single process with multiple threads, so loading, searching and sorting large documents does not require memory equal to the file size.
The Large File Controller, a Professional feature, opens only part of a file. When you open a file above a set size, the controller offers From, To and Size sliders. You choose a section and EmEditor loads that range. After editing a partial view, saving writes the complete file back as one file.
A wizard splits the current document into several files every set number of lines or before each bookmarked line, and another combines several documents into one file.
CSV, TSV and other delimited data
EmEditor Professional detects CSV and TSV files and shows them in CSV mode, with separators aligned so the columns line up like a table. You can define other delimiters as custom formats. A Heading option freezes the first line as a header row.
In cell selection mode the editor behaves more like a spreadsheet. Dragging the AutoFill handle copies a value or continues a number series. Flash Fill completes a column from the pattern it finds in the other columns. Columns can be inserted, moved, copied, extracted, combined or split.
The analysis tools include:
- sorting by one column or by several columns at once;
- Join CSV, which merges two CSV files on key columns using SQL-style join types;
- pivot tables built inside the document, plus Unpivot and Transpose for reshaping data;
- Delete Duplicate Lines, which can bookmark duplicates instead of removing them.
Filtering lines
The Filter Bar hides every line that does not contain the text you enter, leaving only matching lines on screen. It filters as you type and accepts regular expressions, case and whole-word matching. In CSV mode the filter can target column values. The Advanced Filter dialog combines several conditions, and Extract All pulls the matching lines out of the document.
Searching and replacing text
Find and Replace accept plain text, fuzzy matching for near matches, escape sequences such as \t for a tab, and number ranges. The regular expression engine follows Perl syntax, including lookahead, lookbehind and capture groups reused in the replacement.
Batch Replace expands the Replace dialog into a list of find-and-replace pairs, each with its own options. You can import pairs from a TSV file. Batch Replace All applies every pair in turn.
Find in Files and Replace in Files work across the files in a folder. Replace in Files leaves the changed files open and unsaved, with replacements highlighted. You can check or undo the replacements before saving.
Comparing two documents
Compare places two open documents side by side, colors the differences and scrolls both panes together. Generate Report saves the differences to a file as a table. EmEditor Free compares with default options only.
Macros and scripting
You can record a macro by pressing Start Recording, performing the actions and pressing Stop. EmEditor turns the steps into an editable script. You can write scripts in JavaScript or VBScript. JavaScript runs on either the older JScript engine or the V8 engine, which supports modern syntax.
Macros run from the menu or toolbar, from a keyboard shortcut, or automatically when a document is opened, saved or changed. EmEditor Free can only record and play back macros.
Plug-ins, external tools and AI chat
Plug-ins are limited to Professional. Ten come preinstalled, among them Projects, Explorer, Snippets, Web Preview and Word Count. External Tools add buttons or shortcuts that launch other programs.
AI features come in the separate ChatAI plug-in. Chat with AI connects to Anthropic, DeepSeek, Google or OpenAI models with your own API key. It can also connect to a local model served through LM Studio or another OpenAI-compatible server. With tool access enabled, the assistant can read or modify the open document. AI-assisted writing suggests the next text as you type.
Coding and editing aids
For source code, EmEditor provides syntax highlighting and syntax checking for HTML, CSS, JSON and XML. It also provides Language Server Protocol and EditorConfig support, bracket completion and an outline view. Other tools include multiple and vertical selections, binary editing, clipboard history, bookmarks, spell checking and encoding conversions such as Base64.
Free and Professional editions
EmEditor Free covers core editing such as syntax highlighting, Find and Replace, Unicode support and printing. It lacks the Large File Controller, CSV tools, sort, duplicate removal, the Filter Bar, plug-ins and scriptable macros. Its license allows personal use only at home or school, not in companies, government or other organizations. EmEditor Professional is available as an installer, a portable version and a Microsoft Store app.
