Free Online RRC & NAS Decoder
Decode RRC and NAS protocol messages for free, directly in your browser. No signup, no installation, no credit card. Paste your hex frame, click Decode, and get instant results powered by a native C++ ASN.1 engine with 3GPP Release 17 support. Works on any device with a web browser — desktop, tablet or mobile.
What you get for free
The HiCellTek free decoder plan gives you production-grade RRC decoding at no cost. Every feature listed below is available immediately, with no registration or payment.
- ✓ 20 RRC decodes per day
Decode up to 20 RRC messages every day. The counter resets at midnight UTC. Each decode processes one hex frame of any size or complexity.
- ✓ Automatic logical channel detection
The engine detects DL-DCCH, UL-DCCH, BCCH-BCH, BCCH-DL-SCH, PCCH and other channels automatically. No manual configuration needed.
- ✓ Tree, raw and table output views
Switch between interactive tree view, raw ASN.1 text and structured table view to analyze decoded messages in the format that suits your workflow.
- ✓ 2G GSM, 4G LTE and 5G NR support
Decode RRC messages from any generation: 3G UMTS (TS 25.331), 4G LTE (TS 36.331) and 5G NR (TS 38.331), including SA and NSA modes.
- ✓ 3GPP Release 17
Full R17 compliance including CellGroupConfig extensions, FR2 bands, NR-DC configurations and updated measurement reporting structures.
- ✓ .txt export
Export your decoded results as plain text files. Useful for documentation, sharing with colleagues and archiving decoded messages.
- ✓ No signup, no email, no credit card
Start decoding in seconds. No account creation, no email verification, no payment details. Open the decoder and paste your hex frame.
Free vs Pro comparison
| Feature | Free | Pro (29 €/mo) |
|---|---|---|
| RRC decoding | 20/day | Unlimited |
| NAS decoding | ✗ | ✓ |
| Batch mode | ✗ | Up to 1,000 frames |
| JSON export | ✗ | ✓ |
| Advanced filters | ✗ | ✓ |
| Logical channel detection | ✓ | ✓ |
| 3GPP R17 | ✓ | ✓ |
| Signup required | No | Account required |
Why free matters
Telecom professionals around the world need fast access to protocol decoding tools. Field engineers working on cell site issues cannot always wait for license approvals or software installations. Students learning 3GPP protocols need hands-on tools that match what they read in specifications. Operators in emerging markets often work with constrained budgets where every software license is scrutinized. A free, browser-based decoder removes all these barriers. Paste a hex frame, get a decoded result — no friction, no delays.
For HiCellTek, offering a free decoder tier is a commitment to the telecom community. It demonstrates the quality of our native C++ ASN.1 engine and builds trust with engineers who may later need Pro features like NAS decoding, batch mode or JSON export. The free plan is not a trial — it is a permanent tool that professionals and learners can rely on every day.
How to use the free decoder
Open the decoder
Go to the decoder page. No download, no install. Works in Chrome, Firefox, Safari and Edge.
Select technology
Choose 3G UMTS, 4G LTE or 5G NR and the logical channel (DL-DCCH, UL-DCCH, BCCH, etc.).
Paste & decode
Paste your hexadecimal frame from QMDL, PCAP, Wireshark, QCAT or any capture tool. Click Decode.
Analyze & export
Browse the decoded tree, switch between views, then export to .txt for your records.
Who benefits from the free plan
Field engineers
Decode RRC messages on-site during drive tests and troubleshooting. Diagnose attach failures, handover issues and VoLTE drops without installing desktop software. The browser-based decoder works on any laptop or tablet in the field.
Telecom students
Learn 3GPP protocol structures by decoding real-world RRC messages. Visualize ASN.1 trees interactively and compare decoded output with specification text. The free plan provides enough daily decodes for coursework and lab exercises.
Protocol analysts
Quickly verify RRC message content during protocol analysis sessions. Check CellGroupConfig parameters, measurement configurations and SIB broadcasts without switching to a full desktop tool.
Independent consultants
Use the free decoder for client demonstrations, quick protocol checks and ad-hoc troubleshooting. No license management overhead. Upgrade to Pro only when project volume demands unlimited decoding or NAS support.
Upgrade to Pro when you need more
The free plan covers everyday RRC decoding needs. When your workflow demands more, the Pro plan at 29 €/month unlocks the full power of the HiCellTek decoder engine:
- ✓ Unlimited RRC decoding — no daily cap
- ✓ NAS decoding — LTE EPS (TS 24.301) and 5G NR (TS 24.501)
- ✓ Batch mode — decode up to 1,000 frames at once
- ✓ JSON export — structured output for automation and integration
- ✓ Advanced search filters — find specific IEs across decoded results
Related resources
Best Online RRC Decoders 2026
Comprehensive comparison of online RRC decoder tools available in 2026.
HiCellTek vs Marben Decoder
Detailed comparison of HiCellTek and Marben ASN.1 decoders for telecom.
LTE RRC Decoder
Decode LTE RRC messages: RRCConnectionReconfiguration, SIB, TS 36.331 R17.
5G NR RRC Decoder
Decode NR RRC messages: RRCReconfiguration, CellGroupConfig, TS 38.331 R17.
NAS Decoder Online
Decode LTE EPS NAS and 5G NAS messages: Attach, Registration, PDU Session.
Online Decoder vs Wireshark
When to use an online decoder vs Wireshark for protocol analysis.
Frequently Asked Questions
Is the RRC decoder really free?
Yes. The HiCellTek RRC decoder offers 20 free decodes per day with no signup, no email address and no credit card required. Simply paste your hexadecimal frame and click Decode. The free plan includes automatic logical channel detection, tree and raw output views, and support for 2G GSM, 4G LTE and 5G NR up to 3GPP Release 17.
Do I need to create an account?
No. The free plan requires no account creation, no registration and no login. You can start decoding immediately by visiting the decoder page and pasting your hex frame. An account is only needed if you upgrade to the Pro plan for unlimited decoding, NAS support and batch mode.
What are the limits of the free plan?
The free plan allows 20 RRC decodes per day. NAS decoding, batch mode, JSON export and advanced search filters are not included in the free tier. The daily counter resets at midnight UTC. There is no limit on the size or complexity of individual frames.
What does the Pro plan include?
The Pro plan costs 29 EUR per month and includes unlimited RRC and NAS decoding, batch mode for up to 1,000 frames at once, JSON export, advanced search filters and priority support. It covers all protocols: RRC for 2G/3G/4G/5G and NAS for LTE (TS 24.301) and 5G NR (TS 24.501).
Can I use the free decoder for commercial work?
Yes. The free plan can be used for commercial purposes including field troubleshooting, network audits and client reports. There are no license restrictions on how you use the decoded output. The 20 decodes per day limit applies regardless of use case. If you need higher volume, the Pro plan provides unlimited decoding.