# Best Barcodes | Free Label & Barcode Generator (Avery, Uline & Generic Sheets)

Generate, micro-calibrate, and print barcode labels directly in your browser. Upload CSV or Excel spreadsheets, select standard templates compatible with Avery, Uline, and generic unbranded sheets, generate crisp vector SVG barcodes, and calibrate physical print margins in millimeters. 100% free and client-side.

- **Website**: [https://bestbarcodes.com](https://bestbarcodes.com)
- **Machine-Readable Index**: [https://bestbarcodes.com/llms.txt](https://bestbarcodes.com/llms.txt)
- **Full Technical Reference**: [https://bestbarcodes.com/llms-full.txt](https://bestbarcodes.com/llms-full.txt)
- **Sample Spreadsheet**: [https://bestbarcodes.com/sample-data/sample-barcodes.csv](https://bestbarcodes.com/sample-data/sample-barcodes.csv)

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## How It Works in 4 Steps

1. **Input Your Barcode Data**:
   - **Upload Spreadsheet**: Drag & drop or browse `.csv` or `.xlsx` files. Column A contains barcode values; Column B contains product names. Header rows are automatically ignored.
   - **Spreadsheet Fill Mode**: Select **1 Label per Row** (sequential filling) or **Full Page per Row** (each row generates a dedicated full sheet, e.g. 20 rows = 20 full sheets of 30 or 60 labels).
   - **Type or Paste Single**: Enter a single code and description to instantly fill an entire sheet or build a label list one by one.
2. **Select Label Template & Barcode Symbology**:
   - Choose your standard template:
     - **2.25" × 0.75"**: Avery 6870 / Uline S-21844 (30 labels/sheet)
     - **1.75" × 0.66"**: Avery 5195 / Uline S-21929 (60 labels/sheet)
     - **2.625" × 1.00"**: Avery 5160 / Uline S-5042 (30 labels/sheet)
     - **4.00" × 2.00"**: Avery 5163 / Uline S-3845 (10 labels/sheet)
     - **1.75" × 0.50"**: Avery 5167 / Uline S-15183 (80 labels/sheet)
     - **4.00" × 1.00"**: Avery 5161 / Uline S-5044 (20 labels/sheet)
     - **Custom Dimensions**: User-defined grid rows and columns
   - Choose your barcode symbology (UPC-A, EAN-13, Code 128, Code 39, QR Code, etc.).
   - Toggle barcode width (Fixed Centered or Stretch to Fill).
3. **Micro-Calibrate Printer Margins (Millimeters or Inches)**:
   - Adjust Page Top Margin and Page Left Margin to match printer feed tolerances.
   - Fine-tune Inner-Label Offset X and Y to nudge content perfectly inside individual label boundaries.
4. **Print or Download PDF**:
   - Click **Print Labels** for instant vector browser printing (`@page { size: letter; margin: 0; }`).
   - Click **Download PDF** for 300+ DPI high-resolution offline printing.

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## Supported Label Templates (Avery, Uline & Equivalents)

- **2.25" × 0.75" (Avery 6870 / Uline S-21844)**: 3 cols × 10 rows (30 labels/sheet).
- **1.75" × 0.66" (Avery 5195 / Uline S-21929)**: 4 cols × 15 rows (60 labels/sheet).
- **2.625" × 1.00" (Avery 5160 / Uline S-5042)**: 3 cols × 10 rows (30 labels/sheet).
- **4.00" × 2.00" (Avery 5163 / Uline S-3845)**: 2 cols × 5 rows (10 labels/sheet).
- **1.75" × 0.50" (Avery 5167 / Uline S-15183)**: 4 cols × 20 rows (80 labels/sheet).
- **4.00" × 1.00" (Avery 5161 / Uline S-5044)**: 2 cols × 10 rows (20 labels/sheet).

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## Supported Barcode Formats

- **UPC-A (GTIN-12)**: 12-digit US retail codes with wrapped 1-5-5-1 layout.
- **EAN-13 (GTIN-13) / ISBN**: 13-digit retail barcode with snug digit placement and balanced quiet zones.
- **Code 128**: Universal alphanumeric barcodes for warehouse, shipping, and SKU labels.
- **Code 39**: Alphanumeric industrial inventory symbology.
- **UPC-E**: 6-8 digit zero-compressed retail barcodes.
- **EAN-8**: 8-digit international compact retail barcodes.
- **Codabar**: High-reliability numeric libraries and blood bank symbology.
- **Interleaved 2 of 5 (ITF)**: Even-digit numeric warehousing codes.
- **PostNet**: US Postal Service zip codes.
- **QR Code**: 2D matrix barcode for URLs and digital asset tags.

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## Frequently Asked Questions (FAQ)

### How do I align barcodes to prevent bleeding over Avery sheet edges?
Printers have slight physical feed tolerances (typically 0.5 mm to 2.0 mm). Use Step 3 in Best Barcodes to adjust the **Page Top Margin** and **Page Left Margin** by 0.5 mm increments until your test page lines up with the physical label cutouts.

### Are my spreadsheets or customer product data private?
Yes. Best Barcodes is 100% client-side. All CSV/Excel parsing and barcode rendering happen directly inside your web browser. No inventory lists, barcodes, or customer data are ever transmitted to any external server.

### What printer settings should I use?
In your printer dialog:
1. Set **Scale** to **100%** (Do NOT use "Fit to Page" or "Shrink to Fit").
2. Set **Paper Size** to **US Letter (8.5 × 11 inches)**.
3. Set **Margins** to **None** or **Default**.