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CSV File UTF-8 Encoding Error.

Updated October 11, 2026 FAQs 3 min

A merchant platform rejecting your feed with “CSV file is not UTF-8 encoded,” or accented characters showing up as Ã© or ? when you open the file, are both encoding problems. The good news: CTX Feed already writes CSV, TSV and TXT feeds in UTF-8, so in almost every case the file itself is fine — the error comes from how the file is opened, edited, or submitted, not from CTX Feed. This guide explains what UTF-8 encoding is, why the error appears, and how to fix it.

Why this error appears

UTF-8 is the universal text encoding that lets a file hold characters from any language — accents, symbols, non-Latin scripts. When a file isn’t UTF-8, those characters get garbled, and platforms like Google Merchant Center refuse it. The three common causes:

You opened the feed in Excel, edited it, and re-saved it. Excel often re-saves CSV in a local Windows encoding (like Windows-1252), which is not UTF-8. Uploading that re-saved copy is the number-one cause of this error.
You downloaded the file and re-uploaded a copy that passed through a tool that changed the encoding.
A product contains invalid characters — text pasted from Word, a corrupted description, or content stored in a non-UTF-8 database — so a few bytes in the file aren’t valid UTF-8.

Fix 1 — Submit the feed URL, don’t upload a re-saved file

This solves the vast majority of cases. Instead of downloading the CSV, editing it, and uploading the file, give the channel your feed URL directly:

Go to CTX Feed → Manage Feeds.
In the Feed URL column, click Copy to copy the feed’s public URL.
Paste that URL into the channel’s scheduled-fetch setting (Google Merchant Center → Feeds → Add primary feed → Scheduled fetch; Meta Commerce Manager → Data sources → Scheduled feed).

Because the channel fetches the file CTX Feed generated — untouched, UTF-8 — the encoding is always correct, and every regeneration is picked up automatically. Never open the file in Excel and re-upload it.

Fix 2 — Turn on the UTF-8 BOM for Excel

If you need to open the file in Excel and see characters correctly, add a byte-order mark (BOM). A BOM is a few invisible bytes at the start of the file that tell Excel “this is UTF-8.” CTX Feed has an opt-in setting for this:

Open the feed in Make Feed (edit it from Manage Feeds).
In Feed settings, find the UTF-8 BOM dropdown (it appears for CSV, TSV and TXT feeds).
Choose Add UTF-8 BOM — the hint reads “Prepend a byte-order mark so Excel reads it as UTF-8.”
Save & generate.

Leave this off (No BOM) for feeds you submit by URL, since some importers prefer a plain UTF-8 file without a BOM. Use it only when Excel is your audience.

Fix 3 — Open the file the right way

If you just need to view the data without breaking it:

Google Sheets — File → Import → Upload; Sheets reads UTF-8 correctly by default.
Excel — don’t double-click the file. Open Excel, then use Data → From Text/CSV, and in the import dialog set File Origin to 65001: Unicode (UTF-8).
Whatever you do, if you plan to send the file to a channel, don’t save over it from Excel — export the CTX Feed file fresh or use the URL.

Fix 4 — Clean the source data

If a specific field or product breaks the file, the character is likely coming from your product content:

Re-type or paste-as-plain-text any description copied from Word or a PDF, which can carry hidden non-UTF-8 characters.
On a problem column, set the mapping row’s Output column to UTF-8 Encode (or Strip Tags) to sanitize the value before it’s written.
Confirm your WordPress database uses a UTF-8 charset (utf8mb4); most modern installs already do.

Troubleshooting

Google still says “not UTF-8 encoded.” You’re almost certainly uploading an Excel-saved copy. Switch to the feed URL (Fix 1) and remove the manually uploaded file.
Characters look fine in Excel but the channel rejects the file. Turn the UTF-8 BOM off — a BOM you added for Excel can upset a strict importer. Submit by URL.
Only one product breaks the feed. Open that product and clean its description or title (Fix 4), then regenerate.
The feed looks empty or truncated after the bad character. That’s a sign of an invalid byte mid-file; clean the offending product’s content and regenerate.