Text File Merger
Combine plain-text files in the order you choose, customize what is added before and after every file, and download one merged file.
1. Add plain-text files
Choose files or drag them into the box. TXT, FASTA, CSV, Markdown, code, logs, and other plain-text formats are supported.
2. Choose the output settings
The beginning and ending text below are applied separately to every file. The original file contents are not otherwise changed.
Enter any extension you need, such as .txt, .fasta, .md, or .csv. If no extension is entered, .txt is added.
Default: the filename followed by one blank line. Clear this box to add nothing before each file.
Default: two blank lines after every file. Clear this box to add nothing after each file.
Use \n for a new line, \t for a tab, and \\ for a literal backslash. Available placeholders in either box: {filename}, {index}, and {size}.
{filename}\n\n[file contents]\n\n\n
3. Merge and download
Files are combined locally in this browser. They are not uploaded to SequoraDNA or another server.
Supported files and important limitations
This tool joins file contents; it does not convert document formats. TXT and FASTA are the primary intended formats, but the app does not block other file extensions.
If a selected file is not a .txt or .fasta file, the app displays a warning and then allows the file to be added. Binary or structured files may produce unreadable or invalid output because this tool simply concatenates their contents.
For valid FASTA, CSV, JSON, XML, YAML, and code output, clear the beginning and ending boxes unless the added text is valid for that format. This tool does not reconcile repeated CSV headers, combine data structures, or validate a file format.
Best results come from UTF-8 or ASCII text files. UTF-8 byte-order marks are removed during merging. Other encodings are not converted or blocked, so mixed encodings may produce unexpected results.
Large-file thresholds are conservative guidance rather than universal browser limits. Actual capacity depends on the browser, device, operating system, and available memory.
