twineconvert

free · in-browser · no upload

OPT to CSV
Converter

Drop your OPT file. We'll convert it to CSV right here in your browser, your file never leaves your device.

or drop your file

Select your file here to get started

or drop your file here.

Accepts .opt

nothing uploaded no file size cap no signup

How it works

Three steps. No upload, no signup.

  1. 1

    Drop your file

    Click the dropzone above or drag a OPT from your desktop. Files of any size, there's no upload, so there's no upload limit.

  2. 2

    Convert in your browser

    The conversion runs entirely in this tab using JavaScript and WebAssembly. Your file never touches our servers, we don't have any.

  3. 3

    Download

    Get your CSV the moment the conversion finishes. Convert another, or close the tab.

Files stay on your device

Your file is never uploaded. The entire conversion runs in your browser using WebAssembly. We can't see what you convert because we have no server to see it.

No file size limit

Server converters cap free users at 1-2 GB and gate larger files behind a paid plan. Since nothing uploads, our limit is whatever your browser can handle.

Free, no signup, no ads on conversions

No account required. No watermark on the output. No queue. Drop a file, get a converted file.

Why convert OPT → CSV

What this conversion is actually for

OPT files map every Bates page in a production to its image file path on disk. Loading them into Excel directly preserves the data but loses the column meaning — you're stuck remembering that column 4 is `IsBoundary` and column 7 is `PagesInDoc`. Converting to a real CSV with proper headers makes the file self-documenting and shareable across teams without a Concordance manual.

A real example

Your firm received a production where the image folder structure looks broken — some pages are missing TIF files. Drop the OPT, get a CSV, sort by ImagePath, and immediately see the 47 pages with empty path values that need to be re-requested from opposing counsel.

Troubleshooting

Image paths use backslashes and break in my Mac/Linux tool.

Concordance is Windows-native and OPT files use Windows path separators (`\`). We preserve them verbatim. To convert for Mac/Linux: search-replace `\` → `/` in the resulting CSV. If your downstream tool needs absolute paths, prepend the production root to ImagePath.

Formats involved

About OPT and CSV

OPT, Concordance image load file

OPT is the comma-separated image-mapping file that accompanies a DAT in a Concordance/Relativity production. Each row describes one page: PageID (Bates number), Volume, ImagePath (TIF, PDF, or JPG), IsBoundary (Y for first page of a doc), GroupIdentifier, Type, PagesInDoc. Required to load production images alongside the metadata.

How to open

Concordance and Relativity load OPT directly when ingesting a production. Excel opens the comma-separated content but loses the implicit column meanings. Convert to CSV with proper headers for paralegals reviewing image-to-Bates mappings.

Full OPT format guide →
CSV, Comma-Separated Values

CSV is plain text, one row per line, fields separated by commas. The simplest possible tabular data format, which is exactly why it remains the most portable: every spreadsheet, database, programming language, and analytics tool reads CSV. Tradeoffs: no formulas, no formatting, no multiple sheets, and various edge cases around quoting fields that contain commas or newlines.

How to open

Excel, Google Sheets, Apple Numbers, LibreOffice Calc, any text editor, every database import wizard, every programming language with one line of code.

Full CSV format guide →

Related tools

Convert other files to CSV

FAQ

Common questions

Is this OPT → CSV converter really free?

Yes. No signup, no watermark, no daily file count limit. Every conversion runs in your browser, your file never touches our servers because there are no servers.

Where does my file go when I convert it?

Nowhere. The conversion runs entirely in your browser using JavaScript and WebAssembly. Your file is never uploaded to our servers. We don't have any servers handling files, there's nothing for us to log, store, or accidentally leak.

What's the maximum file size?

Whatever your browser can hold in memory. Practically, this means a few hundred MB on most computers, significantly larger than the 1-2 GB caps that server-upload converters charge for. Very large files (multi-GB) may require closing other browser tabs first.

Why convert OPT to CSV?

Mapping production document images to Bates page identifiers. Universal tabular data interchange. The most common reason to convert is compatibility, CSV works in places where OPT doesn't, or vice versa.

How do I open a OPT file in the first place?

Concordance and Relativity load OPT directly when ingesting a production. Excel opens the comma-separated content but loses the implicit column meanings. Convert to CSV with proper headers for paralegals reviewing image-to-Bates mappings.

Does this work offline?

Once the page is loaded, the conversion itself runs entirely offline. The first time you use a tool, your browser downloads the conversion library (a one-time cache). If you reload while offline, the page won't load, but you can install the site as a Progressive Web App for full offline use.

Can I convert multiple files at once?

Single file at a time for now. Batch conversion is on the roadmap, for now, drop one file, download the result, then convert the next.