Free Texture Packer — a TexturePacker Alternative in the Browser
A free packer that goes past "MaxRects + trim": the smallest sheet among the free packers tested on all five real frame sets (rotation allowed), frames restored pixel-exact, and exports that Godot, Unity, Phaser, PixiJS, Spine and LÖVE actually loaded.
Nerulio's Pack & Export is a free, browser-based packer that covers TexturePacker's rectangle packing: MaxRects, trim modes, rotation, merging identical sprites, extrude, border and shape padding, multipack and scale variants. Against TexturePacker Pro 8.3.0 on five real frame sets, with rotation allowed, it made smaller sheets on four and a 2.1 % larger one on the fifth; both tools restored every frame exactly. TexturePacker Pro stays ahead on polygon packing, GPU texture formats, its 68 data formats and a command line for build pipelines.
- Godot 4Verified· Godot 4.7.2
- Unity 6Verified· Unity 6000.5.3f1
- Phaser 3 / 4Verified· Phaser 3.90 + 4.2
- PixiJS 8Verified· PixiJS 8.21
- Aseprite JSONVerified· Phaser load.aseprite · PixiJS 8.21
- .asepriteVerified· Aseprite 1.3.18
- Spine / libGDXVerified· spine-canvas 4.2
- Starling / Sparrow XMLVerified· Phaser 4.2
- LÖVEVerified· LÖVE 11.5
- DefoldBuilt· Defold bob.jar 1.13.1
- GameMakerUNVERIFIED
- CSS spritesVerified· Chromium
- GIF / APNGDecoded· Pillow
What a TexturePacker alternative has to cover
TexturePacker's settings come down to a few decisions: how to cut each sprite (trim mode), how to space them (border padding, shape padding, extrude), whether to rotate, whether identical sprites are stored once, how large a page may be, and which data format to write. Nerulio has an equivalent for each of these rectangle settings; the table below maps the names.
The two differ outside rectangle packing. TexturePacker can trace a polygon around each sprite and pack the polygons, writes compressed GPU formats and reduced pixel formats, and has a command line and .tps project files for build scripts. Nerulio writes PNG only and has no command line; in exchange it carries animations (tags, per-frame durations, pivots, hit boxes) into engine bundles that were loaded in the engines themselves.
Sheet size depends on the page shape you accept. TexturePacker's Best mode keeps the smallest area even when the page becomes a long strip (3551 × 102 on one set); Nerulio scores squarer pages higher. That is why the measurement also compares both tools with square pages forced.
Measured: TexturePacker Pro 8.3.0 and Nerulio, same settings
Trim on, shape padding 2, max 4096, identical sprites merged, best effort on both sides. Δ is Nerulio's sheet area relative to TexturePacker's; negative means Nerulio's sheet is smaller (docs/H2H-PAID.md, 2026-09-25).
set (frames) rotation allowed rotation off square pages
ninja (6) −17.7 % −16.9 % −20.6 %
archer (10) −3.6 % +0.8 % (TP: 3034 × 538 strip) −2.6 %
samurai (60) −5.8 % −8.7 % −10.0 %
toon (45) −2.0 % +3.0 % (TP: 3551 × 102 strip) −3.6 %
spaceshooter (294) +2.1 % (TP: 3575 × 256) +1.2 % +0.8 %
power-of-two pages identical sizes on all five sets
frames restored exact 415 / 415 for both tools in every configuration
polygon mode (TP only) spaceshooter 892,581 px² = 4.5 % below Nerulio's best;
the four character sets 15–27 % larger than TP's own rectanglesSo neither tool wins every row. TexturePacker is ahead on the spaceshooter pack (294 sprites in 96 sizes) and on two sets when rotation is off and long strips are acceptable; Nerulio is ahead on the character sets and with square pages.
TexturePacker settings and their Nerulio equivalents
| TexturePacker | Nerulio Pack & Export | Note |
|---|---|---|
| Trim mode None / Trim / Crop, keep position / Crop, flush position | none / trim / crop-keep / crop, plus an alpha threshold | Same four ideas; crop-keep moves the pivot so the art stays in place |
| Trim mode Polygon, algorithm Polygon | — | Not available: rectangles only |
| Algorithm MaxRects | MaxRects with BSSF, BLSF, BAF, BL and CP, plus Skyline and Guillotine; "try all" keeps the smallest page | Effort fast / normal / best instead of pack modes |
| Extrude, Border padding, Shape padding | extrude 0–32, border padding 0–64, shape padding 0–64 (default 2) | Same meaning, in pixels |
| Allow rotation | Allow rotation, set by each engine preset and enforced at export | Refused for Godot, Unity, Phaser, LÖVE, XML and CSS |
| Detect identical sprites | Alias (hash + byte check), on by default | Both stored the 18 ninja frames of the duplicate test as 6 |
| Multipack, max size, size constraints POT, force squared | Multipack up to 64 pages, 8–16384 px, POT, square, fixed, multiple-of | — |
| Scale variants | @0.5x, @1x, @2x, @3x, @4x | Nearest-neighbour only; no smooth filters, no Scale2x/Hq2x |
| Texture format and pixel format (PVR, ETC, ASTC, DXT, Basis, WebP, RGBA4444 …) | PNG only, indexed when a page has 256 colours or fewer | Convert afterwards if a platform needs GPU formats |
What it does
- MaxRects (BSSF, BLSF, BAF, BL, CP), Skyline and Guillotine with a best-of search; rotation where the engine reads it.
- Trim / crop-keep / crop with an alpha threshold, alias of identical frames (hash + byte check), extrude, border and shape padding.
- POT, square, fixed and multiple-of sizes, multipack up to 64 pages, @0.5x–@4x variants, premultiplied alpha.
- Head-to-head on 5 real CC0 frame sets vs CodeAndWeb's free web packer, GAPTools and free-tex-packer: smallest sheet on all 5 with rotation allowed; every frame exact.
How to do it
- Drop your frames (or a GIF / .aseprite file).
- Pick the preset for your engine and adjust trim, padding and size.
- Check the used % and the frame list.
- Export — each target shows how it was verified before you click.
Other ways to do it
| Option | When it is the better choice |
|---|---|
| TexturePacker Pro | Mobile or console builds that need PVRTC, ETC2, ASTC or Basis textures; sprite packs with angular shapes, where polygon packing saved 4.5 % on the spaceshooter set; build pipelines driven by its command line and .tps files; engines Nerulio has no target for, such as cocos2d, SpriteKit, Unreal Paper2D or MonoGame. |
| TexturePacker's own Godot importer plugin | You already publish from TexturePacker and want Godot to reimport on every change. According to CodeAndWeb it creates one AtlasTexture per sprite and an AnimationLibrary running at 10 fps, not SpriteFrames; compared on TexturePacker to Godot. |
| Nerulio Pack & Export | Free and nothing to install; animations with per-frame durations, pivots and boxes must reach Godot, Unity, Phaser, PixiJS, LÖVE or Spine; you want to see which engine run backs each export before you click. |
| Free web packers and free-tex-packer | Measured on the free packer comparison; free-tex-packer's npm core runs in a build script, which Nerulio cannot. |
Engine exports and how each was checked
"Verified" means the exported files were loaded by the real engine or tool on real CC0 assets and the result was compared with the source. Anything that was not loaded is labelled as such.
| Target | Files | Check |
|---|---|---|
| Godot 4 | .tres SpriteFrames · .tscn AnimatedSprite2D · .png.import | Verified Godot 4.7.2Loaded by Godot; every animation frame drawn and compared with the source file. The scene uses Nearest filtering; rotation is never used. |
| Unity 6 | .unity.json · Editor/NerulioSpriteImporter.cs · AnimationClip | Verified Unity 6000.5.3f1Batch mode: sprite rects, pivots, pixels, clip keys and durations checked. |
| Phaser 3 / 4 | atlas JSON (multiatlas) · .anims.json | Verified Phaser 3.90 + 4.2Frames and animations drawn by both versions. |
| PixiJS 8 | spritesheet JSON · animations · anchor · meta.scale | Verified PixiJS 8.21Rotated and multi-page atlases included. |
| Aseprite JSON | hash / array · frameTags · slices | Verified Phaser load.aseprite · PixiJS 8.21Tags keep their direction and repeat count. |
| .aseprite | layers · tags · durations · slices | Verified Aseprite 1.3.18Opened and rendered by the Aseprite command line. |
| Spine / libGDX | .atlas | Verified spine-canvas 4.2Every region drawn by the Spine runtime, rotated and trimmed; libGDX itself was not run. |
| Starling / Sparrow XML | XML per page | Verified Phaser 4.2Phaser 3.90 draws trimmed XML frames wrongly (its own bug); the "Sparrow XML (Phaser 3)" preset turns trim off and passes in 3.90 and 4.2. |
| LÖVE | Lua quads · nerulio_atlas.lua · main.lua | Verified LÖVE 11.5Every frame drawn and every animation stepped through the shipped helper. |
| Defold | .atlas · .tilesource | Built Defold bob.jar 1.13.1Built by Defold's command-line builder; the built texture's UVs were read back. |
| GameMaker | spr_<name>_stripN.png · gamemaker.json | UNVERIFIEDNot loaded in GameMaker (no headless GameMaker). The strips are cut the way its strip importer cuts them. |
| CSS sprites | .css · preview .html | Verified ChromiumEvery class drawn from the shipped stylesheet. |
| GIF / APNG | one file per animation | Decoded PillowEvery frame and delay decoded again after export; APNG is exact. |
Evidence
Exports: 49 runs in the real engines on real CC0 assets, 47 pass — the 2 failures are Phaser 3.90's trimmed-XML bug, which the Phaser 3 preset avoids. Packer head-to-head on 5 real frame sets (CodeAndWeb free web packer, GAPTools, free-tex-packer): smallest sheet on all 5 with rotation allowed, 4 of 5 without; every frame restored pixel-exact.
What Nerulio lacks compared with TexturePacker Pro
- No polygon packing, rectangles only: TexturePacker's polygon mode was 4.5 % smaller on the spaceshooter set and 15–27 % larger on the four character sets than its own rectangles.
- PNG pages only: no PVRTC, ETC1/2, ASTC, DXT, Basis, KTX, WebP or JPG, and no reduced pixel formats such as RGBA4444 or RGB565 with dithering.
- 17 export targets against TexturePacker's 68 data formats; no cocos2d, SpriteKit, Unreal Paper2D, MonoGame or Solar2D output.
- No command line, smart folders or project file for automated builds; packing runs in the browser.
- Scale variants use nearest-neighbour only, which suits pixel art but not smooth art that needs filtered downscaling.
- Pack speed was not compared fairly: the browser worker was not timed on the same five sets.
Limits
- Polygon (mesh) packing is not offered: none of the verified engines draws a mesh atlas from exported data.
- GameMaker strips are UNVERIFIED in GameMaker itself.
- Scale variants (@0.5x–@4x) use nearest-neighbour only.
- Trimmed Starling XML is drawn wrongly by Phaser 3.90; use the "Sparrow XML (Phaser 3)" preset there.
Versions and sources
Measured on 2026-09-25 with TexturePacker 8.3.0 (Pro trial, command line) and the same modules the Studio runs. Every frame was restored from each tool's JSON and compared pixel by pixel; engine checks ran in Phaser 3.90.0 and 4.2.1, PixiJS 8.21.0, spine-canvas 4.2.120 and Godot 4.7.2. TexturePacker's setting names are taken from its documentation.
Official documentation used
Questions
Can I use the output commercially?
Yes. There is no licence tier and nothing is watermarked or recoloured.
Does it do polygon packing?
No. None of the engines in the verification harness draws a mesh atlas from exported data, so it could not be verified; rectangles only.
Is it free, and do I need an account?
Everything on these pages is free and works without an account. There is no watermark and no export that is held back.
Are my sprites uploaded?
No. The Studio decodes, packs and exports in this browser tab. Projects are autosaved in the browser (IndexedDB) and can be saved as a .nerulio file.
Does it need Aseprite or an engine plugin installed?
No. .aseprite files are read and written in the browser, and each engine bundle carries what that engine needs (for Godot, the import settings and scene; for Unity and the Godot TileSet, a small editor script).