Unexpected token ï in JSON at position 0: what it means and how to fix it
JavaScript: Fix "Unexpected token ï in JSON at position 0": payload starts with a UTF-8 BOM () or invisible leading character. Strip BOM and validate...
Strip BOM (UTF-8 BOM)
A practical hub for Strip BOM (UTF-8 BOM): what it means, common pitfalls (padding, UTF-8, URL-safe chars), and fast local fixes (no upload).
TL;DR: Validate locally, pinpoint the failing spot, apply the minimal fix, then validate again.
Fast no-upload workflow
- Validate the input (strict rules, correct encoding, correct delimiter/quotes).
- Locate the exact position/line reported by the parser or validator.
- Fix the smallest broken part (often a quote, escape, delimiter, or a truncated copy/paste).
- Re-validate and only then convert/export.
Recommended tools
Relevant guides
This list is auto-picked from existing guides. If you don’t see your exact case, use: search guides for “bom utf-8 strip”.
SyntaxError: Unexpected token ï in JSON at position 0: what it means and how to fix it
Node.js: Fix "Unexpected token ï in JSON at position 0": payload starts with a UTF-8 BOM () or invisible leading character. Strip BOM and validate lo...
Encoding issues in CSV/JSON: UTF‑8, BOM, and weird characters
Fix encoding issues like UTF‑8 BOM, strange header characters, and broken symbols in CSV/JSON. Convert locally and validate output (no upload).
illegal base64 data at input char (RawURLEncoding): what it means and how to fix it
Go: illegal base64 data at input char (RawURLEncoding): what it means and how to fix it: decode/encode safely, avoid UTF-8 pitfalls, and keep data local...
Guides by topic
Browse troubleshooting and conversion guides grouped by topic (JSON, CSV, XML, YAML, encoding, config formats, privacy).
Base64URL vs hex encoding
Base64URL vs hex encoding: normalize '-'/'_', add '=' padding, then decode/convert safely with local tools (no upload).
atob/btoa explained: Base64 in the browser (UTF-8 pitfalls)
atob/btoa explained: Base64 in the browser (UTF-8 pitfalls): decode/encode safely, avoid UTF-8 pitfalls, and keep data local (no upload).
Invalid character in the given encoding: causes and fixes
XML parser: Invalid character in the given encoding: root causes, first-fix checklist, and local XML validation workflow (no upload).
Base64URL to UTF-8 text: safe decode workflow (avoid mojibake)
Base64URL to UTF-8 text: safe decode workflow (avoid mojibake): normalize '-'/'_', add '=' padding, then decode/convert safely with local tools (no uplo...
Go: Convert Base64URL to text safely (UTF-8)
Go: Convert Base64URL to text safely (UTF-8): normalize '-'/'_', add '=' padding, then decode/convert safely with local tools (no upload).
Search tools by keyword
Open tools search for “bom utf-8 strip”.
Related subtopics
- Unicode escape sequences (\uXXXX)
- URL encode/decode: safe no-upload workflow
- URL encoding basics (%XX)
- Safe decoding workflow (don’t paste secrets online)
- Query string to JSON: safe no-upload workflow
- Plus (+) vs space in query strings
Related by intent
- Intent hub for Strip BOM (UTF-8 BOM)
- Execution playbook
- Method comparison
- Alternative flows
- Migration path
- Benchmark baseline
- Case study
- Trend report
- Cluster pillar
- Cross-cluster pillar: Privacy
- Linkable data asset
Expert signal
Expert note: Strip BOM (UTF-8 BOM) usually resolves fastest when triage starts from strict validation and then branches to comparison/alternative paths based on input quality.
Data snapshot 2026
| Metric | Value |
|---|---|
| Intent confidence score | 90/100 |
| Predicted CTR uplift potential | 32% |
| Target crawl depth | < 3 clicks |
Trust note: All processing happens locally in your browser. Files are never uploaded.
FAQ (quick)
Start here: URL Encode/Decode (runs locally, no upload).
Can I fix Strip BOM (UTF-8 BOM) without uploading my data? Yes. no-upload.ru tools run locally in your browser (NO UPLOAD). Start with URL Encode/Decode and keep samples redacted if you must share them.
What is the fastest safe workflow? Validate first, fix the smallest broken part, then validate again before converting/exporting. This prevents silent downstream issues.
Why does Strip BOM (UTF-8 BOM) happen? Most issues come from copy/paste truncation, wrong encoding, non-strict syntax (comments/trailing commas), or a shape mismatch (array vs object).
Which tool should I start with for Strip BOM (UTF-8 BOM)? Start with URL Encode/Decode. If you still see errors, follow the related playbook/trend report on this page.
Privacy & Security
All processing happens locally in your browser. Files are never uploaded.