Models › chandra family

datalab-to OpenRAIL out 7 months ago

5.30B parameters, images and text in, text out, 256K tokens of context.

Verified 2026-10-25 Rank #289 in LLMs · score 84.2 method v1 Sources 3 Downloads 30d 1.4M · #93 of 619 tracked

Can I run it?3.2GB at INT4Estimatefits a 16 GB cardmethod
Can I use it?OpenRAILUse-based restrictions apply; read the riderlicence file2026-10-24
Do people use it?1.4Mdownloads, 30 days#93 of 619 we track · top 15%+12 likes, downloads −9% this week573 likesHugging Face2026-10-24

Worth reading

Picked by rule from 8 tracked pieces: the lab's own post, the most shared, a field report, the latest.

Latest · 3 months ago

What Chandra's 85.9% OCR score does not tell you — CarlosDev

Chandra 2 is a 5-billion-parameter model built on Qwen 3.5 that achieves 85.9% on the olmOCR benchmark and processes 1.44 pages/second on an H100.

  • The multilingual benchmark is Chandra's own exam where the authors state no good public multilingual alternative exists.
  • A page that is 95% correctly transcribed can be 100% wrong about the one field you needed.
nullkdev.github.io 2026-07-29 1.1k words about the chandra family family

8 best of 8 tracked

The 1 pick above, plus these 7. Top is the radar's score: discussion, source authority and the lab's own posts, fading with age.

  1. Codedatalab-to/chandra: OCR model that handles complex ...github.com · undated
  2. ArticleAnnouncing Chandra OCR 2: 90+ Languages, Top ...datalab.to · undated
  3. ArticleChandra OCR 2 — Intermediate Documentation (Freemium) | THE D*AI*LY BRIEFberi.net · undated
  4. Articlechandra-ocr v0.2.0pypi.org · undated
  5. ArticleChandra Ocr 2 — Hardware Requirements & Compatibility | llmrunllmrun.dev · undated
  6. ArticleOpen Source OCR Gets a Massive Upgrade How Chandra OCR 2 Processed 27000 Papers in 30 Hours — ML Hivemlhive.com · 2026-04-18
  7. Articledatalab-to/chandra v0.2.0 on GitHubnewreleases.io · 2026-03-18

Where it's used

Hugging Face does not say who downloads a model or with what. These are the proxies: API providers listing it, quantized builds, fine-tunes/adapters/merges, and Spaces that load it.

No API provider serves it, so its downloads are people running it themselves: 40 quantized builds and 17 Spaces.

  • As a service0no API provider listed
  • On own hardware40quantized builds
  • Built on107 fine-tunes · 3 adapters · 0 merges
  • In apps17Hugging Face Spaces

Top Spaces running it: embedl/hfviewer ♥ 181 · victor/chandra-ocr-2 ♥ 12 · emanforhelp/model-pulse ♥ 5 · aaryanpethkar483/chandra-ocr ♥ 3

Will it fit?

Weights only, an estimate: leave room for the KV cache. Method

Fits a 16 GB card at INT4

About 3.2 GB at INT4, 6.4 GB at FP8, 13 GB at BF16: weights only, so leave room for the KV cache.

16 GB card64 GB Mac2×80 GB8×80 GBINT4: about 3.2 GB of weights (estimate; KV cache and activations extra)INT43.2 GBFP8: about 6.4 GB of weights (estimate; KV cache and activations extra)FP86.4 GBBF16: about 13 GB of weights (estimate; KV cache and activations extra)BF1613 GB
16 GB card64 GB Mac2×80 GB8×80 GBINT4: about 3.2 GB of weights (estimate; KV cache and activations extra)INT43.2 GBFP8: about 6.4 GB of weights (estimate; KV cache and activations extra)FP86.4 GBBF16: about 13 GB of weights (estimate; KV cache and activations extra)BF1613 GB

Estimate params × bytes per param × 1.2 · how we estimate

The story so far

Weights, every dated article, and repo commits on one rail.

3 dated articles and 13 repo commits so far

Teal is the weights (2026-03-16), amber triangles are 3 dated articles (each links to it), grey ticks are repo commits.

AprMayJunJulAugSepOct2026-06-26: 1 repo commit2026-03-18: 2 repo commits2026-03-17: 1 repo commit2026-03-16: 9 repo commitsWhat Chandra's 85.9% OCR score does not tell you — CarlosDev · 2026-07-29Open Source OCR Gets a Massive Upgrade How Chandra OCR 2 Processed 27000 Papers in 30 Hours — ML Hive · 2026-04-18datalab-to/chandra v0.2.0 on GitHub · 2026-03-18Weights 2026-03-16 · 2026-03-16Weights 2026-03-16now
AprMayJunJulAugSepOct2026-06-26: 1 repo commit2026-03-18: 2 repo commits2026-03-17: 1 repo commit2026-03-16: 9 repo commitsWhat Chandra's 85.9% OCR score does not tell you — CarlosDev · 2026-07-29Open Source OCR Gets a Massive Upgrade How Chandra OCR 2 Processed 27000 Papers in 30 Hours — ML Hive · 2026-04-18datalab-to/chandra v0.2.0 on GitHub · 2026-03-18Weights 2026-03-16 · 2026-03-16Weights 2026-03-16now

What people built on it

50 derivatives on the Hub. Which build to run, by runtime: the most downloaded in each class.

50 derivatives on the Hub, most of them quantized

From the Hugging Face model tree; quantized builds in teal, fine-tunes, merges and adapters in greys.

40 quantized (Hugging Face model tree)7 fine-tunes (Hugging Face model tree)3 adapters (Hugging Face model tree)40 quantized7 fine-tunes3 adapters
40 quantized (Hugging Face model tree)7 fine-tunes (Hugging Face model tree)3 adapters (Hugging Face model tree)40 quantized7 fine-tunes3 adapters

All variants →

Reference

Everything else, folded: the full tables, every source.

Benchmarks

40 rows

Benchmarks 40 rows

measured third-party leaderboard rowauthor-reported number from the model card or eval files (40)No confidence intervals unless the source gave them; settings differ between rows, so compare within a benchmark, not across. Date = the benchmark's own date when it gives one, else when we read it.
BenchmarkValueSetting / notesReported byDate
author-reported Multilingual Benchmark (43 Languages)68.4% percentarmodel author2026-10-07
author-reported Multilingual Benchmark (43 Languages)72.8% percentbnmodel author2026-10-07
author-reported Multilingual Benchmark (43 Languages)85.1% percentcamodel author2026-10-07
author-reported Multilingual Benchmark (43 Languages)85.3% percentcsmodel author2026-10-07
author-reported Multilingual Benchmark (43 Languages)91.1% percentdamodel author2026-10-07
author-reported Multilingual Benchmark (43 Languages)94.8% percentdemodel author2026-10-07
author-reported Multilingual Benchmark (43 Languages)85.6% percentelmodel author2026-10-07
author-reported Multilingual Benchmark (43 Languages)89.3% percentesmodel author2026-10-07
author-reported Multilingual Benchmark (43 Languages)75.1% percentfamodel author2026-10-07
author-reported Multilingual Benchmark (43 Languages)83.4% percentfimodel author2026-10-07
author-reported Multilingual Benchmark (43 Languages)93.7% percentfrmodel author2026-10-07
author-reported Multilingual Benchmark (43 Languages)70.8% percentgumodel author2026-10-07
author-reported Multilingual Benchmark (43 Languages)70.4% percenthemodel author2026-10-07
author-reported Multilingual Benchmark (43 Languages)78.4% percenthimodel author2026-10-07
author-reported Multilingual Benchmark (43 Languages)90.1% percenthrmodel author2026-10-07
author-reported Multilingual Benchmark (43 Languages)82.1% percenthumodel author2026-10-07
author-reported Multilingual Benchmark (43 Languages)91.6% percentidmodel author2026-10-07
author-reported Multilingual Benchmark (43 Languages)94.1% percentitmodel author2026-10-07
author-reported Multilingual Benchmark (43 Languages)86.9% percentjamodel author2026-10-07
author-reported Multilingual Benchmark (43 Languages)73.2% percentjvmodel author2026-10-07
author-reported Multilingual Benchmark (43 Languages)63.2% percentknmodel author2026-10-07
author-reported Multilingual Benchmark (43 Languages)81.5% percentkomodel author2026-10-07
author-reported olmOCR-bench · Extract text from documents86.9ArXivmodel author2026-10-07
author-reported olmOCR-bench · Extract text from documents89.1Old Scans Mathmodel author2026-10-07
author-reported olmOCR-bench · Extract text from documents92.1Tablesmodel author2026-10-07
Show all 40 rows (15 more)
BenchmarkValueSetting / notesReported byDate
author-reported olmOCR-bench · Extract text from documents51.1Old Scansmodel author2026-10-07
author-reported olmOCR-bench · Extract text from documents91.4Headers and Footersmodel author2026-10-07
author-reported olmOCR-bench · Extract text from documents82.1Multi columnmodel author2026-10-07
author-reported olmOCR-bench · Extract text from documents93.7Long tiny textmodel author2026-10-07
author-reported olmOCR-bench · Extract text from documents99.9Basemodel author2026-10-07
author-reported olmOCR-bench · Extract text from documents85.8 ± 0.8Overallmodel author2026-10-07
author-reported overall (allenai/olmOCR-bench)85.8—Chandra OCR 2 Model Card2026-10-24
author-reported arxiv_math (allenai/olmOCR-bench)86.9—Chandra OCR 2 Model Card2026-10-24
author-reported old_scans_math (allenai/olmOCR-bench)89.1—Chandra OCR 2 Model Card2026-10-24
author-reported table_tests (allenai/olmOCR-bench)92.1—Chandra OCR 2 Model Card2026-10-24
author-reported old_scans (allenai/olmOCR-bench)51.1—Chandra OCR 2 Model Card2026-10-24
author-reported headers_footers (allenai/olmOCR-bench)91.4—Chandra OCR 2 Model Card2026-10-24
author-reported multi_column (allenai/olmOCR-bench)82.1—Chandra OCR 2 Model Card2026-10-24
author-reported long_tiny_text (allenai/olmOCR-bench)93.7—Chandra OCR 2 Model Card2026-10-24
author-reported baseline (allenai/olmOCR-bench)99.9—Chandra OCR 2 Model Card2026-10-24

What the card says

1 cited sentence

Summary generated, cited

Chandra OCR 2 is a 5.30B parameter image-text-to-text model designed to extract text from images and PDFs into markdown, HTML, or JSON formats.[1][2][3]

  1. parameters human
  2. pipeline tag
  3. “outputs markdown, HTML, and JSON”

Generated 2026-10-07 15:08 UTC by parasail-gemma-4-26b-a4b-it; each numeral points at the fact it rests on. Not a verdict.

Use-case evidence

8 use cases

What it is good at 8 use cases

Labels are evidence, not verdicts: measured a third-party leaderboard row for this model; author-reported a number the model author published in the card or eval files; structural a deterministic signal from the name, config or chat template, or a decision-model estimate. Each chip links to its source. All use cases.

Facts

19 fields

Listed in LLMs

Facts

Pipeline tagimage-text-to-text
Librarytransformers
ArchitecturesQwen3_5ForConditionalGeneration
Model typeqwen3_5
Dtypebfloat16
Params by dtypeBF16: 5,295,564,288
Size bandM
MoEno
Context length262,144 (config.json max_position_embeddings)
LicenseOpenRAIL (openrail)
Hub snapshot2026-10-25

Servability

vLLM · SGLang

Servability

vLLM: supported · Qwen3_5ForConditionalGeneration · 7050ef881ff0835f6890a47db1859a24c65481d6SGLang: supported · Qwen3_5ForConditionalGeneration · 773cb938fe9484a8f7e7e46fb1b1fe96412c59ed

vLLM registry (7050ef881ff0835f6890a47db1859a24c65481d6) · SGLang registry (773cb938fe9484a8f7e7e46fb1b1fe96412c59ed) · Matched by architecture class name against each project's registry on main; 'supported' means the architecture is registered, not that this checkpoint was tested.

Hardware fit

3 estimates

Hardware fit ESTIMATE

Weights-only memory for chandra-ocr-2: params × bytes/param × 1.2 overhead. KV cache and activations are extra. How this is computed.

BF16 (2 bytes/param)13 GB · Single GPU (<24 GB)
FP8 (1 byte/param)6.4 GB · Single GPU (<24 GB)
INT4 (0.5 bytes/param)3.2 GB · Edge (<4 GB)

Weights only (params × bytes/param × 1.2 overhead); KV cache and activations extra.

All variants

40 variants

Lineage

Original model Family: datalab-to/chandra 50 derivatives on the Hub

quantized: 40finetune: 7adapter: 3

Top variants (40 shown, ranked by downloads)

Relation
Quant
Size
40 rows
Variant Relation Quant Params Band License Author Likes Downloads
prithivMLmods/chandra-ocr-2-GGUF quantized GGUF — — other prithivMLmods 42 87.9k
dangvansam/chandra-ocr-2-NVFP4A16 quantized — 3.42B M openrail dangvansam 3 28.2k
dangvansam/chandra-ocr-2-FP8-dynamic quantized -FP8 4.54B M openrail dangvansam 2 22.5k
dangvansam/chandra-ocr-2-NVFP4 quantized NVFP4 3.42B M openrail dangvansam 1 6.2k
jwindle47/chandra-ocr-2-8bit-mlx quantized -8bit 4.54B M other jwindle47 4 3.3k
SandLogicTechnologies/chandra-ocr-2-GGUF quantized GGUF — — apache-2.0 SandLogicTechnologies 4 2.5k
hyojk2001/chandra-ocr-2-Q4_K_M-GGUF quantized GGUF — — openrail hyojk2001 3 943
jbarrow/joecr-chandra-2-eagle3.1 finetune — 852M S apache-2.0 jbarrow 8 511
gotoashishgupta/chandra-ocr-2-bf16-8 quantized -bf16 4.54B M openrail gotoashishgupta 0 845
Sohailhosseini/chandra-ocr-2-AWQ-W4A16 quantized AWQ 4.54B M openrail Sohailhosseini 3 637
dougvk/chandra-ocr-2-BF16-GGUF-RDNA4 quantized -BF16 — — other dougvk 0 608
fwgpiyawudk/chandra-ocr-2-bf16-mlx finetune -bf16 4.54B M openrail fwgpiyawudk 0 445
1qh/chandra-ocr-2-8bit-mlx quantized -8bit 4.54B M openrail 1qh 1 368
shinshekai/chandra-ocr-2-Q8_0-GGUF quantized Q8_0 — — openrail shinshekai 1 310
Yashp2003/chandra-ocr-2-ggufs quantized gguf — — — Yashp2003 0 329
lalalalalaa/chandra-ocr-2-mlx-mixed-4-8 quantized mlx 4.54B M openrail lalalalalaa 2 217
tyh-carl/chandra-ocr-2-bf16 finetune -bf16 4.54B M openrail tyh-carl 0 287
kielCAC/chandra-ocr-2-Q2_K-GGUF quantized Q2_K — — openrail kielCAC 0 253
1qh/chandra-ocr-2-oq8-mlx quantized mlx 4.54B M apache-2.0 1qh 0 234
1qh/chandra-ocr-2-mixed-3-8-mlx quantized mlx 4.54B M openrail 1qh 0 207
tyh-carl/chandra-ocr-2-8bit finetune -8bit 1.52B S openrail tyh-carl 0 204
1qh/chandra-ocr-2-4bit-mlx quantized -4bit 4.54B M openrail 1qh 0 186
tyh-carl/chandra-ocr-2-4bit finetune -4bit 991M S openrail tyh-carl 0 182
1qh/chandra-ocr-2-bf16-mlx finetune -bf16 4.54B M openrail 1qh 0 179
nawazsarwar/chandra-ocr-2-Q4_K_M-GGUF quantized GGUF — — openrail nawazsarwar 0 170
1qh/chandra-ocr-2-nvfp4-mlx quantized nvfp4 4.54B M openrail 1qh 0 161
Prince-1/chandra-ocr-2-onnx quantized — — — openrail Prince-1 0 141
1qh/chandra-ocr-2-mxfp4-mlx quantized mxfp4 4.54B M openrail 1qh 0 107
1qh/chandra-ocr-2-mxfp8-mlx quantized fp8- 4.54B M openrail 1qh 0 96
1qh/chandra-ocr-2-oq4-mlx quantized mlx 4.54B M apache-2.0 1qh 0 90
1qh/chandra-ocr-2-mixed-4-8-mlx quantized mlx 4.54B M openrail 1qh 0 85
1qh/chandra-ocr-2-oq6-mlx quantized mlx 4.54B M apache-2.0 1qh 0 82
1qh/chandra-ocr-2-6bit-mlx quantized mlx 4.54B M openrail 1qh 0 78
1qh/chandra-ocr-2-oq5-mlx quantized mlx 4.54B M apache-2.0 1qh 0 78
1qh/chandra-ocr-2-3bit-mlx quantized mlx 4.54B M openrail 1qh 0 77
1qh/chandra-ocr-2-mixed-3-5-mlx quantized mlx 4.54B M openrail 1qh 0 66
1qh/chandra-ocr-2-oq2-mlx quantized mlx 4.54B M apache-2.0 1qh 0 65
1qh/chandra-ocr-2-oq2p7-mlx quantized mlx 4.54B M apache-2.0 1qh 0 63
1qh/chandra-ocr-2-mixed-3-4-mlx quantized mlx 4.54B M openrail 1qh 0 57
1qh/chandra-ocr-2-oq2p5-mlx quantized mlx 4.54B M apache-2.0 1qh 0 57

Repository changelog

13 commits

Repository changelog 13 commits

DateCommitSHA
2026-06-26 Adjust scoring 85.9 -> 85.8 af93b47
2026-03-18 Add olmOCR-bench evaluation results (#1) 808e461
2026-03-18 Update README.md 7ac4bb1
2026-03-17 Update README.md 95dad30
2026-03-16 Update README.md 8b665b1
2026-03-16 Update README.md dc725ba
2026-03-16 Update README.md fd4dbc1
2026-03-16 Update README.md 29577c3
2026-03-16 Upload datalab-logo.png 754c774
2026-03-16 Update README.md ae2fdeb
2026-03-16 Upload 5 files a2128a5
2026-03-16 Upload folder using huggingface_hub 673176e
2026-03-16 initial commit 9829e7c

Articles and coverage

8 pieces

Ranked by source signals (HN, Lobsters, authority domains, official posts) and recency. Summaries are generated from a stored copy of the article text; every sentence cites a span of that text, and nothing is shown that failed the citation check.

Analysis8

github.comauthorityabout the chandra family1,927 words
Chandra 2 achieved an overall accuracy of 85.8 ± 0.8 on internal benchmarks while supporting 90+ languages. The model processes documents at an estimated 2 pages per second in real-world usage on a single NVIDIA H100 80GB GPU.generated, cited
nullkdev.github.io2026-07-29about the chandra family1,128 words
Chandra 2 is a 5-billion-parameter model built on Qwen 3.5 that achieves 85.9% on the olmOCR benchmark and processes 1.44 pages/second on an H100. The weights ship under a modified OpenRAIL-M licence allowing free use for startups under $2M in funding or revenue but prohibiting competition with Datalab's API. RealDocBench indicates that models scoring well on standard benchmarks often show significantly lower accuracy on authentic regulatory documents with field-level requirements.written, reviewed, cited
  • The multilingual benchmark is Chandra's own exam where the authors state no good public multilingual alternative exists.
  • A page that is 95% correctly transcribed can be 100% wrong about the one field you needed.
  • The weights ship under a modified OpenRAIL-M licence that explicitly cannot be used to compete with Datalab's own API.
datalab.to1,553 words
Datalab released Chandra 2, a 4B parameter OCR model that achieves 85.9% on the olmOCR benchmark. The model averages 77.8% on the top 43 languages and processes 2 pages per second on an H100 with 96 concurrent requests. It outputs 15+ block types with bounding boxes and handles complex layouts including tables, math, and Mermaid diagrams.written, reviewed, cited
  • Chandra 2 supports 90 world languages, including significant gains in Indic scripts like Kannada and Malayalam.
  • The model includes an MTP head to further improve latency for on-prem deployment scenarios.
  • The hosted API scores 86.7% on olmOCR overall, outperforming the open model's 85.9%.
beri.net1,142 words
Chandra OCR 2 is a 5B-parameter vision-language model fine-tuned from Qwen 3.5 that converts PDFs and images into structured Markdown, HTML, or JSON while preserving layout. Released in March 2026, it currently tops olmOCR-Bench with an overall score of 85.8, significantly outperforming olmOCR's 82.4 on complex tables and long tiny text. The code is Apache 2.0, but the weights use modified OpenRAIL-M licensing, allowing free use for research and startups under $2M in funding or revenue, while commercial self-hosting requires a paid license.written, reviewed, cited
  • The hosted Datalab API provides zero data retention and SOC 2 Type 2 compliance for sensitive document processing.
  • The vLLM backend achieves approximately 1.44 pages per second on a single H100 80GB GPU at 96 concurrent sequences.
pypi.orgabout the chandra family2,575 words
Chandra OCR 2 converts images and PDFs into structured HTML, Markdown, or JSON while preserving layout information. Released in 3/2026, the model supports 90+ languages and offers two inference modes: local (HuggingFace) and remote (vLLM server). The code uses an Apache 2.0 license while model weights require a modified OpenRAIL-M license.written, reviewed, cited
  • Engineers can start their own vLLM server using the datalab-to/chandra-ocr-2 model instead of relying on the hosted API.
  • The model weights license prohibits competitive use with the company's hosted API unless the user obtains broader commercial licensing.
llmrun.dev1,382 words
mlhive.com2026-04-181,633 words
Chandra OCR 2 is a 5-billion parameter open-source model that processes documents as direct image-to-markdown translations. The team processed 27,000 arXiv papers in under 30 hours, sustaining a speed of approximately 3.5 pages per second. Deploying on an 8x H100 cluster costs roughly $900 for the full test, utilizing torch.compile and Flash Attention 2 for efficiency.written, reviewed, cited
  • Models in the 1B range frequently hallucinate numbers in dense financial tables or drop crucial negative signs in mathematical formulas.
newreleases.io2026-03-18about the chandra family307 words

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Sources

3 sources

Sources

Hub snapshot: 2026-10-25 · HF API: 2026-10-24 21:37 UTC · Providers: 2026-10-24 21:44 UTC · Articles: 2026-10-24 21:45 UTC · Summary: 2026-10-07 15:08 UTC · Last verified 2026-10-25

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