SixLabors/ImageSharp · error · InvalidImageContentException

Unable to read Gif image data

Error message

Unable to read Gif image data

What it means

Thrown when a GIF signature was recognized but no image data follows — the decoder found a header yet no Image Descriptor or blocks. Raised as InvalidImageContentException to report that the GIF body is empty.

Solutions

1. Regenerate the GIF ensuring at least one image block is written
2. Check the producing pipeline — an empty animation export commonly causes this
3. Validate minimum file size / presence of an image descriptor before decoding
4. Catch InvalidImageContentException and treat the asset as invalid in your ingest pipeline

Example fix

// before
var image = Image.Load(stream);
// after
try { var image = Image.Load(stream); }
catch (InvalidImageContentException ex) when (ex.Message.Contains("image data")) { MarkAssetInvalid(assetId); }

// Ensure the GIF has at least one image descriptor (0x2C) after the header
byte[] all = File.ReadAllBytes(path);
bool hasImageBlock = all.AsSpan(13).IndexOf((byte)0x2C) >= 0;
if (!hasImageBlock) throw new InvalidDataException("GIF contains no image data");

try { return Image.Load(stream); }
catch (InvalidImageContentException ex) when (ex.Message.Contains("Unable to read Gif image data")) { return RegenerateOrSkip(stream); }

When it happens

Trigger: Image.Load/Decode on a file that begins with a valid GIF header+screen descriptor but ends (or contains only extensions) before any image data block.

Common situations: Empty/placeholder GIFs created by buggy tools, files truncated right after the header, or assets uploaded as 0-image GIFs from a broken pipeline.

Understand the failure class

Background: EmptyResultError / "no results found": when an API or scraper succeeds but returns zero rows — this error's family across 9 libraries.

Related errors

• Gif image does not contain a Logical Screen Descriptor.
• Invalid EXR image header
• Unexpected end of stream while reading gif application…
• Invalid gif colormap size
• The ANI file does not contain any frame resources.

AI-assisted analysis of SixLabors/ImageSharp@59ce6af6fc (2026-09-13). Data as JSON: /api/errors/aa8804970a2b58fa. Report an issue: GitHub.

Appendix: source

Thrown at src/ImageSharp/Formats/Gif/GifThrowHelper.cs:18

// Copyright (c) Six Labors.
// Licensed under the Six Labors Split License.

using System.Diagnostics.CodeAnalysis;

namespace SixLabors.ImageSharp.Formats.Gif;

internal static class GifThrowHelper
{
    [DoesNotReturn]
    public static void ThrowInvalidImageContentException(string errorMessage)
        => throw new InvalidImageContentException(errorMessage);

    [DoesNotReturn]
    public static void ThrowNoHeader() => throw new InvalidImageContentException("Gif image does not contain a Logical Screen Descriptor.");

    [DoesNotReturn]
    public static void ThrowNoData() => throw new InvalidImageContentException("Unable to read Gif image data");
}

View on GitHub (pinned to 59ce6af6fc)