File size limits by format
Filelume.biz processes files locally in your browser. Limits vary by format because different file structures use different amounts of browser memory.
The largest file this app will open is a 10.0 MB Log. Every other format is lower — the table below is the whole answer, and it is the same table for everyone.
| Format | Category | Maximum size |
|---|---|---|
| Markdown | Text & code | 2.0 MB |
| SQL | Text & code | 2.0 MB |
| TXT | Text & code | 2.0 MB |
| HTML | Structured data | 2.0 MB |
| JSON | Structured data | 2.0 MB |
| XML | Structured data | 2.0 MB |
| YAML | Structured data | 2.0 MB |
| TOML | Structured data | 512.0 KB |
| SVG | Vector graphics | 2.0 MB |
| CSV | Tabular data | 5.0 MB |
| Log | Line-based data | 10.0 MB |
| JSONL | Line-based data | 3.0 MB |
| XLSX(compressed) | Spreadsheet | 1.0 MB |
| DOCX(compressed) | Document | 1.0 MB |
Important notes
- Compressed formats are checked twice. XLSX and DOCX are ZIP packages. The size in the table is the file on disk; after unpacking, the contents are checked against a second cap of 10.0 MB. Office documents typically compress at about 9:1, so an ordinary file under the first cap clears the second.
- Structure has limits too. An Office file can sit under the size cap and still be refused as unusually complex:Worksheets per workbook50Rows per worksheet50,000Cells per workbook500,000Paragraphs per document50,000Embedded images200
- Browser-local:Your files stay in your browser. No upload, no server processing. The caps exist because your browser's memory is the machine doing the work — which is also why a phone may struggle with a file a laptop opens comfortably.
Frequently asked questions
Why are JSON limits lower than CSV?
JSON usually needs a complete nested structure in memory, while CSV can be processed progressively by rows.
Why are the XLSX and DOCX limits so much lower than the rest?
Because the number that matters is the unpacked size, not the packed one. A 1.0 MB Word file expands to roughly the 10.0 MB the cap allows. Publishing the compressed figure is what keeps the refusal at the moment you choose the file, instead of partway through opening it.
Is there a paid plan with bigger limits?
No. Filelume.biz has one tier and it is free, so these limits are not a price boundary — they are the point at which a browser tab stops being able to do the work reliably.
Can I open a file larger than the limit?
To protect browser stability, Filelume.biz cannot process files above the maximum safe limit. Try splitting the file into smaller parts.
Everything else is unlimited in the way that matters
There is no cap on how many files you open, no sign-up, and no feature held back for a plan that does not exist.
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