Combine multiple text-based files into one — plain text, source code, JSON, YAML, XML, and Markdown — right in your browser. Reorder them, clean them up (minify, beautify, strip comments, remove duplicate lines), choose how they're joined, and download the result. Nothing is uploaded: every merge runs locally on your device, so source code, configs, and private notes never leave your machine.
Best Fit
- Concatenate log files, notes, or Markdown into a single document.
- Combine source files into one blob to paste into ChatGPT or Claude as context.
- Merge JSON or YAML config fragments with a clear strategy (array, append, or deep merge).
- Clean up merged code: remove comments, collapse whitespace, or beautify in one pass.
How to use File Merger
- Drop files — or a whole folder — onto the drop zone, or click Browse.
- Reorder them by dragging; the merge follows the list order.
- Pick a mode (Text, Code, JSON, YAML, XML) and set options: separators, filename headers, and transforms.
- Watch the live preview update, then Copy or Download the merged output.
What File Merger helps with
- Every text-based format — plain text, Markdown, source code, JSON, YAML, and XML.
- Value transforms — language-aware comment removal, beautify / pretty-print, minify, and remove duplicate lines.
- Exclude files — skip
node_modules, lockfiles, or minified files with.gitignore-style patterns before merging. - Pack for AI — bundle code files into one LLM-ready blob with a directory tree, your choice of plain / Markdown-fenced / XML wrapping, and an approximate token count.
- JSON merge strategies — wrap all files in an array, append sequentially, or deep-merge with last-value-wins.
- Privacy by default — processing happens in your browser; nothing is sent to a server.
Examples
Combine three text files
Input: intro.txt, body.txt, notes.txt in order, with filename headers and a separator between each.
Output: one document with each file under its own ── filename ── header, joined by your chosen separator, ready to copy or download as merged_output.txt.
Pack a code folder for ChatGPT
Input: a src/ folder of .js files, Code mode, Pack for AI enabled, Markdown format, directory tree on.
Output: an ASCII tree of the folder followed by each file in a fenced ```js block, with an estimated token count so you know whether it fits your model's context limit.
Frequently asked questions
Are my files uploaded anywhere? No. Merging runs entirely in your browser. Your files — including source code and credentials in config files — never leave your device.
How do I combine my code for ChatGPT or Claude? Add your files (or a folder), enable "Pack for AI", pick a wrapping format, and copy the result. The token counter tells you if it fits the model's context window.
What's the best JSON merge strategy? Use array to collect standalone objects, append for sequential fragments that don't share keys, and deep merge when files share a schema and later values should win.
Can it remove comments or minify? Yes. Turn on the transform options to strip comments (it picks the right comment syntax per file type), beautify/pretty-print, collapse whitespace, or drop duplicate lines across the merged output.
Is there a file or size limit? Merges are bounded by your browser's memory since everything runs locally; very large files are best split first.
Which formats are supported? Text-based files only — plain text, Markdown, source code (JS, TS, CSS, HTML, SQL, Python, and more), JSON, YAML, and XML. Binary formats like PDF and Word are not supported, since everything runs locally in your browser.
