Free tool

LEGO Missing Piece Checker

Rule out the usual hiding places first. If the piece really is gone, check the set piece by piece and leave with the element ID LEGO asks for, or a link to buy the part.

Micro World

Checking

21102 Micro World

471 pieces in 54 part and color combinations, plus 2 minifigures.

The piece count includes the 8 parts inside the set's minifigures, which this inventory lists separately. Spare parts are counted in neither figure.

Before you call it missing

Builders who report a missing piece often find it in one of these places. Tick each one off as you look.

Look-alike colors in this set

These parts appear in this set in two colors that are easy to confuse. If you are one short in one color, check whether it went in where the other color belongs. Each color has its own element ID in the parts list at the back of the instructions.

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Piece checklist

Light Bluish Gray 130 pieces

  • Brick 1 x 1 Light Bluish Gray Part 3005 Element 4211389 ×2
  • Brick 1 x 2 Light Bluish Gray Part 3004 Element 4211388 ×3
  • Brick 1 x 3 Light Bluish Gray Part 3622 Element 4211428 ×17
  • Brick 1 x 4 Light Bluish Gray Part 3010 Element 4211394 ×8
  • Brick 1 x 6 Light Bluish Gray Part 3009 Element 4211393 ×5
  • Brick 2 x 2 Light Bluish Gray Part 3003 Element 4211387 ×4
  • Brick 2 x 2 Corner Light Bluish Gray Part 2357 Element 4211349 ×22
  • Plate 1 x 1 Light Bluish Gray Part 3024 Element 4211399 2 spares in the box ×32
  • Plate 1 x 2 Light Bluish Gray Part 3023 Element 4211398 or 3023194 ×9
  • Plate 1 x 4 Light Bluish Gray Part 3710 Element 4211445 ×2
  • Plate Special 1 x 4 with 2 Studs, 3 Bottom Tubes Light Bluish Gray Part 92593 Element 4599498 ×4
  • Tile 1 x 1 with Groove Light Bluish Gray Part 3070b Element 4211415 1 spare in the box ×9
  • Tile 1 x 2 with Groove Light Bluish Gray Part 3069b Element 4211414 ×2
  • Tile 1 x 3 Light Bluish Gray Part 63864 Element 4558169 ×4
  • Tile 1 x 4 with Groove Light Bluish Gray Part 2431 Element 4211356 or 2431194 ×3
  • Tile 1 x 6 with Groove Light Bluish Gray Part 6636 Element 4211549 ×4

Dark Bluish Gray 87 pieces

  • Brick 1 x 1 Dark Bluish Gray Part 3005 Element 4211098 Also in Black ×2
  • Brick 1 x 2 Dark Bluish Gray Part 3004 Element 4211088 ×10
  • Brick 1 x 3 Dark Bluish Gray Part 3622 Element 4211104 ×4
  • Brick 2 x 2 Dark Bluish Gray Part 3003 Element 4211060 ×3
  • Brick 2 x 2 Corner Dark Bluish Gray Part 2357 Element 4211109 ×7
  • Plate 1 x 1 Dark Bluish Gray Part 3024 Element 4210719 1 spare in the box Also in Black ×27
  • Plate 6 x 6 Dark Bluish Gray Part 3958 Element 4211134 ×4
  • Technic Brick 1 x 2 with Axle Hole Type 1 [+ Opening] and Bottom Pin Dark Bluish Gray Part 32064a Element 6178919 or 4210935 ×18
  • Tile 1 x 1 with Groove Dark Bluish Gray Part 3070b Element 4210848 1 spare in the box ×12

Reddish Brown 78 pieces

  • Brick 1 x 1 Reddish Brown Part 3005 Element 4211242 ×16
  • Plate 1 x 1 Reddish Brown Part 3024 Element 4221744 1 spare in the box ×37
  • Plate 1 x 2 Reddish Brown Part 3023 Element 4211150 ×10
  • Plate 1 x 3 Reddish Brown Part 3623 Element 4211152 ×1
  • Plate 2 x 3 Reddish Brown Part 3021 Element 4211189 ×1
  • Plate 6 x 6 Reddish Brown Part 3958 Element 4217848 ×4
  • Tile 1 x 1 with Groove Reddish Brown Part 3070b Element 4211288 1 spare in the box ×9

Green 76 pieces

  • Plate 1 x 1 Green Part 3024 Element 302428 1 spare in the box ×12
  • Plate 1 x 3 Green Part 3623 Element 4107758 or 362328 ×2
  • Tile 1 x 1 with Groove Green Part 3070b Element 4558593 or 4238528 1 spare in the box ×62

Tan 31 pieces

  • Plate 1 x 1 Tan Part 3024 Element 4159553 or 302405 1 spare in the box ×1
  • Tile 1 x 1 with Groove Tan Part 3070b Element 4125253 1 spare in the box ×30

Blue 14 pieces

  • Plate 1 x 1 Blue Part 3024 Element 302423 1 spare in the box ×1
  • Plate 1 x 2 Blue Part 3023 Element 302323 ×1
  • Tile 1 x 1 with Groove Blue Part 3070b Element 4206330 or 307073 1 spare in the box ×12

Lime 12 pieces

  • Plate 1 x 3 Lime Part 3623 Element 4534664 or 4271564 ×2
  • Tile 1 x 1 with Groove Lime Part 3070b Element 4537251 1 spare in the box ×10

Black 11 pieces

  • Brick 1 x 1 Black Part 3005 Element 300526 Also in Dark Bluish Gray ×1
  • Plate 1 x 1 Black Part 3024 Element 302426 1 spare in the box Also in Dark Bluish Gray ×2
  • Plate 1 x 2 Black Part 3023 Element 302326 ×2
  • Technic Axle 2 Notched Black Part 32062 Element 4109810 or 3206226 ×6

Trans-Clear 10 pieces

  • Plate 1 x 1 Trans-Clear Part 3024 Element 6513962 or 6252041 ×8
  • Plate 1 x 2 Trans-Clear Part 3023 Element 6514001 or 6240204 ×2

Trans-Red 9 pieces

  • Tile 1 x 1 with Groove Trans-Red Part 3070b Element 6581817 or 6254248 1 spare in the box ×9

Red 6 pieces

  • Brick 1 x 1 Red Part 3005 Element 300521 ×4
  • Plate 1 x 1 Red Part 3024 Element 302421 1 spare in the box ×2

Trans-Dark Blue 4 pieces

  • Brick Sloped 30° 1 x 1 x 2/3 (Cheese Slope) Trans-Dark Blue Part 54200 Element 6245256 or 4244366 1 spare in the box ×4

Metallic Gold 2 pieces

  • Tile 1 x 2 with Groove Metallic Gold Part 3069b Element 6546117 or 6265247 ×2

Orange 1 piece

  • Brick and Axle Separator v2.0 Orange Part 96874 Element 6240515 or 4654448 ×1

Minifigures 2 figures

  • Creeper - Micro Minifigure, checked as a whole figure ×1
  • Steve - Micro Minifigure, checked as a whole figure ×1

Tick each piece as you find it, or mark it missing.

When a piece really is missing

Ask LEGO

LEGO takes requests for pieces missing from a new set through its customer service site. The form asks for the set number and each piece's element ID, the number printed beside the piece in the parts list at the back of the instructions. This checker lists both.

Request a replacement from LEGO

Buy the piece

Mark a piece missing and your list links it to an eBay search for that part, which also covers pieces from older or second-hand sets.

Keep a record

Copy or download your missing list (the CSV opens in any spreadsheet), or print the whole checklist and tick pieces off on paper. Your marks stay in this browser, so you can check a big set over several sittings.