Convert base64 to JPEG
Photos and thumbnails in APIs often arrive as base64 JPEG. base64app decodes, detects the JPEG SOI marker, previews the image, and downloads with a .jpg extension.
How it works
- 1. Paste base64 JPEG data above.
- 2. Click Decode to preview.
- 3. Download the .jpg file.
Common errors
- Invalid characters — standard base64 only uses A–Z, a–z, 0–9, +, /, and = padding.
- Missing or wrong padding — length should be a multiple of 4; add = at the end if needed.
- Line breaks and spaces — email, Slack, and JSON often insert whitespace that must be stripped.
- data: URI prefix left on the string — remove data:<mime>;base64, before decoding.
- URL-safe alphabet — JWTs and some APIs use - and _ instead of + and /.
- Truncated payload — a copied string cut off mid-way cannot be fully recovered.
Frequently asked questions
Base64 to JPG or JPEG?
They are the same format. base64app saves JPEG bytes as .jpg.
Does it support data:image/jpeg URIs?
Yes. Paste the full data URI.
Can I decode progressive JPEG?
Yes. Any valid JPEG byte stream decodes correctly.
Is my image uploaded?
No. Decoding is client-side only.
Is my data uploaded when I decode?
No. All processing runs in your browser. Nothing is uploaded, stored, or logged.
Can base64app fix corrupted base64?
Yes. Auto-repair fixes whitespace, data URI prefixes, URL-safe characters, padding, and stray characters.