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) Playbook
Strip BOM (UTF-8 BOM). Actionable remediation checklist with tool links and relevant guides.
TL;DR: Validate -> locate exact failing spot -> fix the minimal part -> re-validate.
Execution steps
- Validate input locally. Start with a validator or parser-friendly converter.
- Locate root cause. Use line/position/error token to isolate one failing place.
- Apply a minimal fix. Do not refactor all content at once.
- Re-validate and continue. Once clean, convert/export safely.
Recommended tools
Relevant guides
Auto-selected from existing guides for this topic. Need more: search by keyword.
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).
Related actions
- Deep topic hub: Strip BOM (UTF-8 BOM)
- Decision comparison: Strip BOM (UTF-8 BOM)
- Alternative flows: Strip BOM (UTF-8 BOM)
- Migration path: Strip BOM (UTF-8 BOM)
- Case study: Strip BOM (UTF-8 BOM)
- Trend report: Strip BOM (UTF-8 BOM)
- Pillar for Encoding
- Data asset: Strip BOM (UTF-8 BOM)
- All Encoding subtopics
- Search tools for "bom utf-8 strip Strip BOM (UTF-8 BOM)"
Related playbooks
- 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.
Privacy & Security
All processing happens locally in your browser. Files are never uploaded.