When an upload says unsupported file type, invalid format, or import failed, do not fix it by renaming the suffix alone. Check the real file header, extension meaning, and size limit first, then inspect text encoding, CSV delimiter/header/column shape, and whether JSONL contains one valid JSON value per line. Re-export, convert, or compress only after the root mismatch is clear. Chakan runs these checks locally in the browser and does not upload user files, scan for malware, or decide whether a platform should approve the file.
Upload / import format diagnostics
Upload file format error, import failed, and unsupported file type troubleshooting
A local workflow for unsupported file type errors, CSV import failures, JSONL line errors, text encoding problems, extension allow-lists, and upload size limits.
unsupported file typeinvalid file format troubleshootingupload file type not allowedCSV import failedJSONL line errorfix file encoding mojibakeupload size limit converterfile extension not supported
Common lookup scenarios
Troubleshoot unsupported file type or invalid file format messages
Check CSV import failures caused by delimiter, header, column count, or mojibake
Find the JSONL line that is not valid JSON before dataset import
Confirm extension, real type, and size before uploading images, PDFs, ZIPs, or attachments
Review exports from spreadsheets, databases, BI tools, AI datasets, or ecommerce admin panels
Share a repeatable pre-upload checklist with teammates
Recommended workflow
- Use file signature viewer to compare the header, browser MIME, and extension
- Use file extension lookup to understand whether the suffix matches the platform allow-list
- Convert MB, MiB, GB, and GiB before deciding whether compression or splitting is needed
- For text files, check UTF-8, UTF-8 BOM, GB18030, Big5, Shift_JIS, EUC-KR, or Windows-1252 before re-exporting
- Preview CSV delimiters, headers, empty columns, row counts, and column consistency before import
- Validate JSONL line by line and convert to a JSON array only after errors are fixed; never expose real file content, import logs, or customer data as public result URLs, sitemap entries, or llms.txt examples
Related tool entries
A local workflow for unsupported file type errors, CSV import failures, JSONL line errors, text encoding problems, extension allow-lists, and upload size limits.
File signature viewer
Inspect a local file header signature, browser MIME type, extension, and likely real file type without uploading the file.
LookupToolChakanFile extension lookup
Look up common file extensions, MIME types, format purpose, text/binary nature, related extensions, and handling tips.
LookupToolChakanFile size converter
Convert file sizes across SI and IEC units and compare decimal vs binary display values.
LookupToolChakanFile encoding viewer and converter
Inspect and convert local text file encodings such as UTF-8, UTF-16, GB18030, Big5, Shift_JIS, EUC-KR, and Windows-1252.
LookupToolChakanCSV table viewer and validator
Preview CSV as a table and validate delimiter, headers, empty rows, duplicate headers, and uneven column counts in the browser.
LookupToolChakanCSV and JSON converter
Convert CSV to JSON or JSON to CSV in the browser with delimiter detection, header handling, and preview rows for imports and docs.
LookupToolChakanJSONL and JSON converter
Convert JSON Lines to a JSON array or JSON arrays to JSONL in the browser, with per-line validation for logs, datasets, and batch APIs.
LookupToolChakanImage format converter
Convert images locally between PNG, JPEG, and WebP with quality controls and output preview.
LookupToolChakanZIP archive viewer
Inspect a local ZIP archive for file count, folder count, extension distribution, estimated original size, and entry list.
LookupToolChakanFAQ
When an upload says unsupported file type, invalid format, or import failed, do not fix it by renaming the suffix alone. Check the real file header, extension meaning, and size limit first, then inspect text encoding, CSV delimiter/header/column shape, and whether JSONL contains one valid JSON value per line. Re-export, convert, or compress only after the root mismatch is clear. Chakan runs these checks locally in the browser and does not upload user files, scan for malware, or decide whether a platform should approve the file.
Can I fix an unsupported file type by changing the extension?
Usually no. Renaming changes only the suffix. If the real header, encoding, delimiter, or platform allow-list does not match, the import can still fail.
Do these import troubleshooting tools upload my file?
No. Header checks, encoding preview, CSV preview, and JSONL validation are designed to run locally in the browser, and user file content does not become a public result URL.
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